STABLE PARENTERAL FORMULATIONS OF DULOXETINE

Information

  • Patent Application
  • 20220409544
  • Publication Number
    20220409544
  • Date Filed
    November 30, 2020
    4 years ago
  • Date Published
    December 29, 2022
    2 years ago
Abstract
The present invention relates to a parenteral lyophilized formulation of duloxetine or a pharmaceutically acceptable salt thereof. Further, this invention relates to duloxetine dissolved in a suitable solvent system comprising one or more buffers, stabilizers, and other pharmaceutically acceptable excipients and subsequently lyophilized. The invention also describes combination formulation of Duloxetine with other active ingredients.
Description
FIELD OF THE INVENTION

The present invention relates to a parenteral dosage form of duloxetine or a pharmaceutically acceptable salt thereof and the method of manufacture of the said dosage form. The parenteral dosage form of this invention provides immediate relief to the patients.


BACKGROUND OF THE INVENTION

Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor (SSNRI), chemically known as (+)—N-methyl-3-(1-naphthalenyloxy)-3-(2-thienyl) propan-1-amine). Duloxetine is not stable in presence of acid and degrades rapidly in acidic environment of the gastrointestinal tract. One of the degradant of acid hydrolysis is 1-napthol, which is known to be toxic and causes several side effects. To avoid the degradation and side effects, duloxetine is supplied as an enteric coated dosage form.


Duloxetine is commercially available in USA as delayed release capsules containing enteric coated duloxetine hydrochloride pellets. The product is sold under the brand name Cymbalta®. Duloxetine is used in the treatment of major depressive disorder, generalized anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia and chronic musculoskeletal pain. The Tlag (time for the absorption to begin) of duloxetine is 2 hours and Tmax (time to reach maximum concentration) is 6 to 10 hours. Hence the product is indicated to be administered 2 hours before the surgery for pain management.


The indications of duloxetine are such that quick onset of action is desirable. This is not possible with the currently available enteric coated formulation where the GI transit time is more than 6 hours. Further, the capsule formulation may present difficulties in swallowing in pediatric and elderly patients. This often leads to discontinuation of treatment and poor patient compliance. There are patents describing oral formulations of duloxetine. For eg, U.S. Pat. No. 5,508,276 discloses an enteric duloxetine pellet formulation comprising a) a core consisting of duloxetine and a pharmaceutically acceptable excipient; b) an optional separating layer; c) an enteric layer comprising hydroxyl propyl methylcellulose acetate succinate (HPMCAS) and a pharmaceutically acceptable excipient. The patent describes the importance of formulating duloxetine as enteric coated pellets for better absorption and bioavailability but does not talk about parenteral formulations of duloxetine.


U.S. Pat. No. 8,758,779 discloses duloxetine powder for oral suspension whereas U.S. Pat. Nos. 8,455,667 and 8,513,439 disclose oral liquid compositions comprising duloxetine with suitable buffers. None of these patents have disclosures for making parenteral formulations.


The prior art formulations are associated with many disadvantages. Some of these are—increased time for absorption and onset of action for the enteric coated formulations, variability in drug absorption in different patients, difficulty in administering the formulations to patients who cannot take oral medication, pediatric and geriatric patients and possible degradation of the drug due to increased time of contact with gastric acids.


Thus, there is a need to make a parenteral formulation of duloxetine that can overcome the disadvantages associated in the prior art. These formulations are particularly advantageous because they result in quick action and relief from pain because the drug enters systemic circulation directly bypassing first pass metabolism and gastric acid degradation.


SUMMARY OF THE INVENTION

The present invention relates to a parenteral formulation of duloxetine comprising duloxetine dissolved in a suitable solvent system comprising one or more buffers, stabilizers and other pharmaceutically acceptable excipients. The formulation is in the form of a lyophilized injection comprising duloxetine.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 01 shows Permiability of various formulations evaluated using Rat Intestine at 15 minutes time (mcg/cm2).





DETAILED DESCRIPTION OF THE INVENTION

The term “duloxetine” is intended to refer to the pharmaceutically acceptable salts, solvates and polymorphs thereof. Duloxetine Hydrochloride is most preferred.


“Water Content” in the pharmaceutical formulation plays a major role in degrading the product. Drug gets degraded when it comes in contact with water, which ultimately effects the self-life of the product. The term “Water Content” in the present invention refers to an amount less than 5% w/w and more preferably less than 3% w/w even after 6 months of storage at accelerated conditions.


The words “Water Content” and Moisture Content” are interchangeable and means the same throughout the specification.


The term “lyophilize” in the context of this invention, is intended to refer to the process of freeze drying of a solution comprising duloxetine and other pharmaceutically acceptable excipients. The term “lyophilizate” refers to the product of lyophilization. The term “reconstitution” refers to dissolution of the lyophilizate for achieving a solution.


The inventors of the present invention defined the term “parenteral” formulation, which means a pharmaceutical formulation that can be administered through intravenous, intramuscular, subcutaneous, intraperitoneal and intrathecal routes of administration.


In one aspect, the present invention relates to a parenteral formulation of duloxetine for preoperative, peri-operative, post-operative pain management to reduce or alleviate need for Opioids and, therefore, opioid-related adverse effects or opioid-induced hyperalgesia, and for management of chronic and acute painful conditions.


The present inventors have now surprisingly found that it is possible to make a duloxetine lyophilized formulation that would overcome the disadvantages associated with prior art.


In one embodiment, the invention encompasses a lyophilized parenteral formulation of duloxetine.


Lyophilization or freeze-drying is a method for dehydrating samples used to preserve or increase stability or to stop degradation. Due to the low water content of lyophilized products, the action of microorganisms and enzymes is inhibited and the product life thereby increased. In lyophilization, the sample to be lyophilized is dissolved in an aqueous solution and subsequently frozen after which the surrounding pressure is reduced. The sample is then submitted to sublimation, optionally by the application of heat, in order to sublime the frozen water directly from the solid phase to the gas phase.


The lyophilized parenteral formulation of this invention comprises duloxetine dissolved in an aqueous vehicle and subsequently lyophilized in appropriate containers or glass vials. The lyophilizate thus formed can be reconstituted with a normal physiological solution like normal saline or with a specific diluent. The aqueous vehicle is preferably a sterile aqueous vehicle that is normally used as liquid vehicle for injection. Suitable aqueous vehicles include, for example, sterile water and sterile aqueous vehicles that contain suitable excipients that promote and preserve the stability of duloxetine after reconstitution.


In another embodiment, the invention relates to a lyophilized formulation comprising (i) duloxetine (ii) a bulking agent, (iii) an aqueous vehicle and (iv) other pharmaceutically acceptable excipients.


Bulking agents are used in lyophilization to increase product mass, adjust tonicity, improve product appearance, prevent product collapse, or aid in rehydration. Bulking agents for the purpose of this invention may be selected from mannitol, dextrose, cyclodextrin, sodium chloride, sorbitol and the like. Mannitol is the most preferred. The bulking agents may make up 1-99% by weight of the lyophilized solid.


The aqueous vehicle can be selected from one or more of buffers selected from the group comprising acetate buffer, phosphate buffer, aspartic acid and boric acid buffer, citrate buffer and glycine buffer, succinate buffer, alanine buffer, valine buffer, histidine buffer, lactic acid buffer and the like. The aqueous vehicle can also contain mixture of process aid solvents like alcohols, acetonitrile, acetone and like that are removed during lyophilization.


The inventors carried out solubility/solution stability studies to determine the solution solubility of duloxetine in various buffers at different pH values. The concentration of the solution was kept at 10 mg/ml,









TABLE 1







Solubility data of duloxetine in various buffers at various pH












Buffer
pH
Observation
Buffer
pH
Observation















Phosphate
4.5
Clear solution
Serine buffer
4.5
Clear solution


buffer


Sodium
4.5
Clear solution

5.5
Clear solution


phosphate


buffer


Acetate
4.5
Clear solution

6.4
Clear solution


buffer
5.5
Clear solution
Lactic acid
4.5
Clear solution



6.4
Clear solution
buffer
5.5
Clear solution



7.5
Clear solution

6.4
Clear solution


Aspartic acid
4.5
Clear solution

7.5
Clear solution


and Boric
5.5
Clear solution
Phosphate
5.5
Insoluble


acid buffer


buffer


Succinate
4.5
Clear solution

6.4
Insoluble


buffer


Glycine
4.5
Clear solution
Sodium
5.5
Insoluble


buffer
5.5
Clear solution
phosphate
6.4
Insoluble





buffer



6.4
Clear solution
Citrate
4.5
Insoluble



7.5
Clear solution
buffer
5.5
Insoluble


Alanine
4.5
Clear solution

6.4
Insoluble


buffer
5.5
Clear solution
Aspartic acid
6.4
Insoluble





and Boric





acid buffer


Valine buffer
4.5
Clear solution
Succinate
5.5
Insoluble



5.5
Clear solution
buffer
6.4
Insoluble



6.4
Clear solution
Tris buffer
4.5
Insoluble



7.5
Clear solution

5.5
Insoluble


Leucine
4.5
Clear solution

6.4
Insoluble


buffer
5.5
Clear solution
Alanine
6.4
Insoluble





buffer



6.4
Clear solution
Phenyl
6.4
Insoluble





alanine





buffer



7.5
Clear solution
Lysine
4.5
Insoluble


Isoleucine
4.5
Clear solution
buffer
5.5
Insoluble


buffer
5.5
Clear solution

6.4
Insoluble



6.4
Clear solution
Histidine
4.5
Insoluble



7.5
Clear solution
buffer
5.5
Insoluble


Methionine
4.5
Clear solution

6.4
Insoluble


buffer
5.5
Clear solution
Tartaric acid
4.5
Insoluble



6.4
Clear solution
buffer
5.5
Insoluble



7.5
Clear solution

6.4
Insoluble


Proline buffer
4.5
Clear solution
Meglumine
4.5
Insoluble



5.5
Clear solution
buffer
5.5
Insoluble



6.4
Clear solution

6.4
Insoluble



7.5
Clear solution
Serine buffer
7.5
Insoluble


Phenyl alanine
4.5
Clear solution
0.1N Sodium
4.5
Insoluble


buffer
5.5
Clear solution
hydroxide
5.5
Insoluble


Tryptophan
4.5
Clear solution
buffer
6.4
Insoluble


buffer
5.5
Clear solution



6.4
Clear solution



7.5
Clear solution









The solution state stability of duloxetine was studied in various buffers for 24 hours. The data is tabulated below:









TABLE 2







Solution state stability of duloxetine in various buffers for 24 hours









Formulation










Aspartic
Aspartic



acid +
acid +














Glycine
Glycine
Acetate
Acetate
Boric Acid
Boric Acid



Buffer
Buffer
Buffer
Buffer
Buffer
Buffer



(pH-5.5)
(pH-6.4)
(pH-5.5)
(pH-6.4)
(pH-5.5)
(pH-6.4)









Condition-RT-25° C.




















I*
24 h
I*
24 h
I*
24 h
I*
24 h
I*
24 h
I*
24 h























pH
5.59
5.5
6.23
6.35
5.32
5.4
6.38
6.1
5.8
5.7
6.6
6.5


Assay (%)
105
104.8
97.7
96.6
93.9
92.4
94.3
90.3
93.0
93.3
97.9
97.8


Total
0.12
0.2
0.10
0.18
0.14
0.2
0.1
0.1
0.3
0.5
0.3
0.5


Impurities





Note:


I*: Initial






The samples were stored for 24 hours and analyzed for pH, assay and total impurities by standard analytical procedures. The data showed that duloxetine has satisfactory stability in all the buffers tested. The acetate buffer at pH-5.5 and pH-6.4 and the glycine buffer at pH-5.5 and pH-6.4 showed best results in terms of assay and total impurities.


In yet another embodiment, the invention relates to a lyophilized formulation comprising (i) duloxetine, (ii) a bulking agent, (iii) an aqueous vehicle, (iv) a stabilizer and (v) other pharmaceutically acceptable excipients.


In yet another embodiment, the invention relates to a lyophilized formulation comprising (i) duloxetine, (ii) a bulking agent (iii) an aqueous vehicle, (iv) a stabilizer, (v) one or more pH adjusting agents and (vi) other pharmaceutically acceptable excipients.


In yet another embodiment, the invention relates to a lyophilized formulation comprising (i) duloxetine, (ii) a bulking agent (iii) an aqueous vehicle, (iv) a stabilizer, (v) one or more surfactants and (vi) other pharmaceutically acceptable excipients.


The lyophilized formulation of the present invention has less than 0.5% w/w of each of the following impurities: duloxetine 4-napthyl isomer ((4-[3-(Methylamino)-1-(thiophen-2-yl)propyl]naphthalen-1-ol), alpha napthol ((Naphthalen-1-01)), duloxetine beta napthol-1-yl isomer ((2-[3-(Methylamino)-1-(thiophen-2-yl)propyl]naphthalen-1-01)). More specifically the above said impurities are less than 0.3% w/w each, even after 6 months of storage under accelerated conditions.


The stabilizer in the formulation can be selected from one or more of DOTA, DTPA, EDTA and the like. The quantity of the stabilizer can be from 0.001% w/w to 10% w/w.


The one or more pH adjusting agents can be selected from the group comprising sodium hydroxide, hydrochloric acid, mineral acids, carboxylic acids and salts thereof.


The surfactants may be selected from the group comprising lecithin, soya lecithin, egg lecithin, PEG-PE, phosphatidyl choline, etc


In yet another embodiment, the invention relates to a kit comprising lyophilized formulation of duloxetine supplied together with a diluent. The diluent supplied in the kit can be selected from water for injection, dextrose solution, normal saline, mannitol solution, dextrose normal saline solution (DNS), half saline solution (with a concentration of sodium chloride at 0.45% w/v), dextrose 5%, Normal saline with Arginine (pH 10.07), Ringer Lactate solution.


The lyophilized formulation of the present invention can be reconstituted with the diluent solution described above. It can be administered directly after reconstitution or may further be diluted with any of the physiologically acceptable solutions at the time of administration.


The lyophilized samples prepared as per the invention were reconstituted with water and normal saline.









TABLE 3







Reconstitution studies of duloxetine lyophilized samples










Batch
Reconstituted media
Initial pH
Observation













1A
Water
4.55
Clear solution


1B

5.56
Clear solution


1C

6.22
Clear solution


1D

4.64
Clear solution


1E

5.43
Clear solution


1F

6.11
Clear solution


1G

4.62
Clear solution


 1 H

5.17
Clear solution


1I

6.02
Clear solution


1A
0.9% Sodium
4.51
Clear solution


1B
chloride
5.52
Clear solution


1C

6.14
Clear solution


1D

4.63
Clear solution


1E

5.43
Clear solution


1F

6.13
Clear solution


1G

4.6
Slightly hazy


 1 H

5.09
Clear solution


1I

6.07
Clear solution


316A 
0.45% Sodium
6.12
Clear solution



Chloride


316A 
Dextrose 5%
5.97
Clear solution


316A 
Dextrose Normal
5.77
Clear solution



Saline


316A 
Normal saline with
7.24
Clear solution



Arginine (pH 10.07)


316A 
Ringer Lactate
6.30
Clear solution









The formulations were observed to be clear upon reconstitution with water, 0.9% Sodium chloride, 0.45% Sodium Chloride, Dextrose 5% Dextrose Normal Saline Normal saline with Arginine (pH 10.07) Ringer Lactate.


All the formulations showed satisfactory description and desired pH range.


Manufacturing Process


The subject-matter of the present invention further relates to a process for preparing the lyophilized formulation and the kit. The process comprises the steps of:


(i) mixing the following components (in any suitable order): duloxetine or a pharmaceutically acceptable salt or solvates thereof; an aqueous vehicle; one or more bulking agents; optionally one or more stabilizers; and optionally one or more pH adjusting agents; to provide for an aqueous preparation, wherein duloxetine has a concentration of 1 to 20% w/v, based on the aqueous preparation;


(ii) lyophilizing the aqueous preparation to provide for the lyophilized formulation in solid form; and optionally


(iii) preparing the diluent and filling in suitable containers or vials; and optionally


(iv) providing the lyophilized formulation and diluent in the form of a kit.


The aqueous preparation may be a suspension/dispersion or solution. The lyophilization step may be carried out in vials, blisters or in any other larger vessel, such as stainless-steel trays or tanks, called “bulk lyophilization”.


The bulk solution prepared in step (i) was evaluated for stability. The data is tabulated below. Stability of bulk solution is important to ensure a quality product even in the case unforeseen prolonged process times. Various concentrations of the drug i.e 10 mg/ml, 20 mg/ml and 30 mg/ml were studied in different pH ranges. The formulations were prepared as per the details of example 1.


Stability data of bulk solution up to 24 h.









TABLE 4A







Stability of bulk solution at a concentration of 10 mg/ml









B. NO











1A
1B
1C









Condition


















24 h
24 h

24 h
24 h

24 h
24 h



Initial
2-8° C.
25° C.
Initial
2-8° C.
25° C.
Initial
2-8° C.
25° C.









Description



Clear and Colourless Solution



Assay (%)
















Related substances
101.9
101.9
102.0
103.4
101.4
102.0
102.4
101.9
102.4








Impurity Name
% w/w



















Duloxetine Alcohol
0.01
0.01
0.02
ND
ND
ND
ND
ND
ND


Duloxetine Napthol 4-yl
0.02
0.02
0.07
0.01
0.01
0.03
0.01
0.01
0.02


isomer


Alpha Napthol
0.03
0.03
0.12
0.01
0.01
0.02
0.01
0.01
0.01


Duloxetine Beta napthol-
0.02
0.02
0.07
0.01
0.01
0.04
0.01
0.01
0.02


1-yl isomer


Duloxetine Related
0.05
0.05
0.05
0.06
0.06
0.06
0.06
0.06
0.04


Compound-F











Total Impurities (%)
0.13
0.13
0.33
0.09
0.09
0.15
0.09
0.09
0.09
















TABLE 4B







Stability of bulk solution at a concentration of 20 mg/ml









B. NO











1D
1E
1F









Condition


















24 h
24 h

24 h
24 h

24 h
24 h



Initial
2-8° C.
25° C.
Initial
2-8° C.
25° C.
Initial
2-8° C.
25° C.









Description



Clear and Colourless Solution



Assay (%)
















Related substances
102.1
101.4
101.8
103.2
101.2
102.1
102.7
101.2
102.0








Impurity Name
% w/w



















Duloxetine Alcohol
0.01
0.01
0.03
ND
ND
0.01
ND
ND
ND


Duloxetine Napthol 4-
0.02
0.02
0.08
0.01
0.01
0.04
0.01
0.01
0.02


yl isomer


Alpha Napthol
0.05
0.04
0.18
0.02
0.02
0.05
0.01
0.01
0.01


Duloxetine Beta
0.02
0.02
0.10
0.01
0.02
0.05
0.01
0.01
0.03


napthol-1-yl isomer


Duloxetine Related
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06


Compound-F











Total Impurities (%)
0.16
0.15
0.46
0.10
0.11
0.21
0.09
0.09
0.12
















TABLE 4C







Stability of bulk solution at a concentration of 30 mg/ml









B. NO











1G
1H
1I









Condition


















24 h
24 h

24 h
24 h

24 h
24 h



Initial
2-8° C.
25° C.
Initial
2-8° C.
25° C.
Initial
2-8° C.
25° C.









Description



Clear and Colourless Solution



Assay (%)
















Related substances
101.4
101.7
101.9
101.6
101.4
103.0
101.1
101.3
102.0








Impurity Name
% w/w



















Duloxetine
ND
0.01
0.03
ND
ND
0.01
ND
ND
ND


Alcohol


Duloxetine
0.02
0.02
0.08
0.01
0.01
0.03
0.01
0.01
0.02


Napthol 4-yl


isomer


Alpha Napthol
0.03
0.03
0.16
0.01
0.01
0.05
0.01
0.01
0.02


Duloxetine Beta
0.01
0.02
0.09
0.01
0.01
0.04
0.01
0.01
0.03


napthol-1-yl


isomer


Duloxetine Related
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06


Compound-F











Total Impurities
0.12
0.14
0.42
0.09
0.09
0.19
0.09
0.09
0.13


(%)









It is evident from the data above that the stability of bulk solution is satisfactory across the pH ranges of 4.5, 5.5 and 6.4 at temperatures of 2-8° c. and 25° c. There is practically no loss in the percentage of drug after 24 hours and no increase in impurities.


In Vitro Ex In-Vivo Permeability Study


For administration of drug through intramuscular, subcutaneous, intraperitoneal, intrathecal, inhalation, and intranasal routes of administration, permeability of drug from the formulation plays a significant role. Thus various formulations were evaluated for permeability flux rate of Duloxetine using invitro ex-vivo rat intestine.


Details of in-vitro and ex-vivo Permeation Study:


a. Experimental Setup:


1. Permeability Barrier setup (intestine preparation):


Wistar Rats of Body weight of 300 (+25) grams were selected and fasted overnight for 12 hours before sacrificing. The animals were sacrificed by cervical dislocation and intestinal segments (jejunum portion) were isolated. The isolated intestine segments were washed with Ringer lactate solution then stored in aerated Ringer solution till usage. 20 cms of intestine segment was selected to fill 2 mL of the sample. Both the ends of the segments were tied with cotton thread ensuring no leakage from the surface and subjected for diffusion study for determining permeability.


2. Sample Preparation:


The formulation of examples of 8A, 16, 17, 6 and 18 were diluted to get concentration of 5 mg/mL of duloxetine in phosphate buffer pH 6.8. 2 mL of each solution was taken in separate.


Wherein above examples contain: (Example 8A; soya lecithin), (Example 16; Egg Lecithin), (Example 17: HPBCD), (Example 6: PEGPE) and Duloxetine API—(Example 18))


3. Experimental Condition and Permeability evaluation:


Diffusion study was performed by placing the intestine segments in 50 mL of oxygenated 6.8 pH phosphate buffer at 37±0.5° C. temperature under rotary shaking at 50 rpm. The intestine acts as donor chamber and diffusion media acts as receptor chamber from which aliquot samples were collected at predefined time points.


4. Sample Collection:


The sample were collected at 15 mins, 30 mins, 45 mins, 1 Hrs, 2 Hrs, 3 Hrs, 6 Hrs, 12 Hrs, 24 Hrs and 48 Hrs. At each time point 1 mL of the sample was collected from the diffusion phase and replaced with equal volume of phosphate buffer of temperature 37±0.5° C. temperature. The samples were analysed using HPLC method for Duloxetine content.


b. Data Evaluation:


The samples collected at each time point were analysed for diffused drug content by HPLC method. The flux rates were calculated from slope of a trend-line plotted by taking cumulative amount drug release form unit surface area (i.e. mcg/cm2) against time (h). The flux rates were calculated using the following equation


(1):






J=m/At  Equation (1)


Where:


J=is the Flux of compound “m” moving through a cross-sectional area “A” during time “t”









TABLE 5







Study summary
















Flux rate






Drug conc. in the
calculated



Sample ID/
Description of
intestinal sac/
(mcg/cm2) at


S. No
Details
sample
Volume
15th minute
Remarks





1
Duloxetine API
Drug dissolved in
2 mL of 5 mg/mL
16.24
Control: API in pH



in pH 6.8
phosphate buffer
solution (10 mg of
mcg/cm2
6.8 Phosphate



Phosphate buffer
without any
Drug in Sac)

Buffer




excipients


2
Duloxetine
Lyophilized
2 mL of 5 mg/mL
48.21
Permeability



formulation with
duloxetine
solution (10 mg of

improved > 3 folds



Soy lecithin
formulation with Soy
Drug in Sac)

over API in buffer




lecithin


3
Duloxetine
Lyophilized
2 mL of 5 mg/mL
54.04
Permeability



formulation with
duloxetine
solution (10 mg of

improved > 3 folds



Egg lecithin
formulation with
Drug in Sac)

over API in buffer




Egg lecithin


4
Duloxetine
Lyophilized
2 mL of 5 mg/mL
38.93
Permeability



formulation with
duloxetine
solution (10 mg of

improved > 2 folds



HPBCD
formulation with
Drug in Sac)

over API in buffer




HPBCD


5
Duloxetine
Lyophilized
2 mL of 5 mg/mL
37.80
Permeability



formulation with
duloxetine
solution (10 mg of

improved > 2 folds



PEG-PE
formulation with
Drug in Sac)

over API in buffer




PEGPE









Accompanying FIG. number 1 illustrates Permeability of various formulations evaluated using Rat Intestine at 15 minutes time (mcg/cm2). The permeability flux rate of duloxetine formulation containing Lecithin's or PEG-PE or Cyclodextrin was found to be increased by 2-3 folds than compared to flux rates of drug solution that does not have any of these excipients.


Duloxetine Combination Formulations


American Pain Society guidelines on management of acute pain and Chronic Non-cancer pain suggests “multimodal analgesia” or “balanced analgesia” for the treatment of postoperative pain management. Multimodal or Balanced Analgesia includes involves the use of more than one method or modality of controlling pain (e.g., drugs from two or more classes, drug plus nondrug treatment) to obtain additive beneficial effects, reduce side effects, or both.


Nearly 50% of the patients who visit hospitals due to pain related illness suffer from acute neuropathic pain, chronic neuropathic pain, post amputation pain, cancer surgeries, post traumatic limb pain and neuropathic pain due to trauma. It would be advantageous to have a parenteral formulation with a combination of another active ingredient like paracetamol or diclofenac or the like with duloxetine that would address the treatment need in such patients. For painful phases of chronic pain management, a short duration of parenteral product usage for quick response s very much desired.


In yet another embodiment, the invention also encompasses an injection formulation comprising (i) duloxetine or a pharmaceutically acceptable salt thereof, and (ii) a second active ingredient, selected from the group comprising paracetamol, diclofenac, gabapentin, pregabalin, dexamethasone, lidocaine, melatonin etc.


The following Examples are intended to illustrate the present invention and are not to be considered as limiting the scope of the invention.


Example 1















Quantity % w/v

















S. No
Ingredients
1A
1B
1C
1D
1E
1 F
1 G
1 H
1 I




















1.
Duloxetine
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00



Hydrochloride


2.
Mannitol
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0


3.
DOTA*
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02


4.
5.0N Sodium
0.02
0.46
0.60
0.19
0.84
1.06
0.96
1.06
1.14



hydroxide Solution


5.
Acetate buffer
84.9
84.5
84.3
84.7
84.1
83.92
84.02
83.9
83.8



(10 mg/mL)



pH
4.5
5.5
6.4
4.5
5.5
6.4
4.5
5.5
6.4





*DOTA—Dodecane tetra acetic acid






Manufacturing Process


1. 80% of required quantity of vehicle for batch is taken in a vessel.


2. Duloxetine was transferred to the above vessel and dissolved by stirring at 400 rpm till the solution turned clear.


3. Mannitol was added to the above drug solution and stirred for 3 minutes till the solution becomes clear.


4. To the above solution, DOTA is added and stirred well for 1 minute till the solution turned clear.


5. The pH of the bulk solution is adjusted by using 5.0N Sodium hydroxide solution.


6. The final volume of the above solution is adjusted with remaining quantity of water for Injection.


7. The bulk solution is filled into vials and lyophilized.


Example 2















S. No
Ingredients
Qty/vial (mg)
Qty % w/v


















1.
Duloxetine Hydrochloride
56.30
3.75


2.
Dextrose monohydrate
50.00
3.33


3.
DOTA*
0.30
0.02


4.
0.1N Sodium hydroxide Solution
0.003
0.0002


5.
Glycine solution (0.5 mg/mL) Q.s
1393.40
92.89





*DOTA—Dodecane tetra acetic acid






Manufacturing Process


1. 80% of required quantity of vehicle for batch is taken in a vessel.


2. Duloxetine was transferred to the above vessel and dissolved by stirring at 400 rpm till the solution turned clear.


3. Dextrose monohydrate was added to the above drug solution and stirred for 3 minutes till the solution becomes clear.


4. To the above solution, DOTA is added and stirred well for 1 minute till the solution turned clear.


5. The pH of the bulk solution is adjusted to 5.5 by using 0.1 N Sodium hydroxide Solution.


6. The final volume of the above solution is adjusted with remaining quantity of water for Injection.


7. The bulk solution is filled into vials and lyophilized.


Example 3

















Example 3A
Example 3B
Example 3C
















Qty/
Qty
Qty/
Qty
Qty/
Qty




vial
%
Vial
%
vial
%


S. No
Ingredients
(mg)
w/v
(mg)
w/v
(mg)
w/v

















1.
Duloxetine
30.0
4.0
60.0
4.0
90.0
4.0



Hydrochloride


2.
Mannitol
60.0
8.0
120.0
8.0
180.0
8.0


3.
DOTA*
0.15
0.02
0.3
0.02
0.45
0.02


4.
5N Sodium
6.78
0.9
13.5
0.9
20.3
0.9



hydroxide



Solution


5.
Acetate buffer
Q.s to
87.08
Q.s to
87.08
Q.s to
87.08



(20 mg/mL)
0.75 mL

1.5 mL

2.25 mL





*DOTA—Dodecane tetra acetic acid






Manufacturing Process


1. 80% of required total batch quantity of vehicle was dispensed and taken in a vessel.


2. Dispensed quantity of API was transferred to the above vessel and dissolved by stirring at 400 rpm till the solution turned clear.


3. Dispensed quantity of Mannitol was added to the above drug solution and stirred for 3 minutes till the solution become clear.


4. To the above solution dispensed quantity of stabilizer (DOTA) was added and stirred well for 1 minute till the solution turned clear.


5. The pH of the bulk solution was adjusted to 5.5 by using 5N Sodium hydroxide solution.


6. Final volume of the above solution was adjusted with remaining quantity of Vehicle.


The formulations were studied for stability.


Stability Study of Duloxetine Formulations









TABLE 6A







Stability study of duloxetine formulation at 30 mg concentration









B. NO



3A



Condition













Initial
4 W-2-8° C.
4 W-25° C.
4 W-30° C.
4 W-40° C.









Strength



30 mg/vial



Description



White Lyophilized Powder


Impurity Name
% w/w















Duloxetine Alcohol
ND
ND
ND
ND
0.01


Duloxetine Napthol 4-yl isomer
0.01
0.01
0.01
0.01
0.03


Alpha Napthol
0.02
0.02
0.02
0.02
0.03


Duloxetine Beta napthol-1-yl
0.01
0.01
0.02
0.02
0.06


isomer


Total Impurities (%)
0.11
0.09
0.13
0.17
0.53


Assay
103.6
101.8
101.9
101.3
101.9


Water Content (mg/Vial)
4.6
4.6
6.2
14.1
7.7





Note:


ND—Not determined,


W—Week













TABLE 6B







Stability study of duloxetine formulation at 60 mg concentration









B. NO



3B



Condition













Initial
4 W-2-8° C.
4 W-25° C.
4 W-30° C.
4 W-40° C.









Strength



60 mg/vial



Description



White Lyophilized Powder


Impurity Name
% w/w















Duloxetine Alcohol
ND
ND
ND
0.01
0.01


Duloxetine Napthol 4-yl isomer
0.01
0.01
0.01
0.03
0.10


Alpha Napthol
0.02
0.02
0.02
0.03
0.07


Duloxetine Beta napthol-1-yl
0.01
0.01
0.02
0.06
0.28


isomer


Total Impurities (%)
0.11
0.09
0.13
0.53
1.66


Assay
102.9
102.0
101.9
100.6
96.8


Water Content (mg/Vial)
9.1
8.4
11.7
10.6
10.7





Note:


ND—Not determined,


W—Week













TABLE 6C







Stability study of duloxetine formulation at 90 mg concentration









B. NO



3C



Condition













Initial
4 W-2-8° C.
4 W-25° C.
4 W-30° C.
4 W-40° C.









Strength



90 mg/vial



Description



White Lyophilized Powder


Impurity Name
% w/w















Duloxetine Alcohol
ND
ND
ND
ND
0.01


Duloxetine Napthol 4-yl isomer
0.01
0.01
0.01
0.01
0.03


Alpha Napthol
0.02
0.02
0.02
0.02
0.03


Duloxetine Beta napthol-1-yl
0.01
0.01
0.02
0.02
0.07


isomer


Total Impurities (%)
0.11
0.09
0.13
0.17
0.54


Assay
100.8
100.0
101.8
99.7
101.4


Water Content (mg/Vial)
12.5
10.8
6.2
14.1
18.5





Note:


ND—Not determined,


W—Week






Example 4

















Qty/vial
Qty


S. No
Ingredients
(mg)
% w/v


















1.
Duloxetine Hydrochloride
60.00
4.00


2.
Mannitol
120.00
8.00


3.
DOTA
0.30
0.02


4.
Acetic acid
10.00
0.67


5.
5N Sodium hydroxide Solution
3.00
0.20


6.
Glycine solution (10 mg/mL) Q.s
Q.s 1.5 mL
87.11









Manufacturing Process


1. 80% of required total batch quantity of glycine solution was dispensed and taken in a vessel.


2. Dispensed quantity of API was transferred to the above vessel and dissolved by stirring at 400 rpm till the solution turned clear.


3. Dispensed quantity of Mannitol was added to the above drug solution and stirred for 3 minutes till the solution become clear.


4. To the above solution dispensed quantity of stabilizer (DOTA/Acetic acid) was added and stirred well for 1 minute till the solution turned clear.


5. The pH of the bulk solution was adjusted to 5.5 by using 5N Sodium hydroxide solution.


6. The bulk solution was lyophilized after filling into vials


Example 5

















Qty/vial
Quantity


S. No
Ingredients
(mg)
% w/v


















1.
Duloxetine Hydrochloride
60.00
4.00


2.
Mannitol
120.00
8.00


3.
DOTA
0.30
0.02


4.
Acetic acid
10.00
0.67


5.
5N Sodium hydroxide Solution
3.00
0.20


6.
Serine solution (10 mg/mL)
Q.s 1.5 mL
87.94









Manufacturing Process


1. 80% of required total batch quantity of Serine solution was dispensed and taken in a vessel.


2. Dispensed quantity of API was transferred to the above vessel and dissolved by stirring at 400 rpm till the solution turned clear.


3. Dispensed quantity of Mannitol was added to the above drug solution and stirred for 3 minutes till the solution become clear.


4. To the above solution dispensed quantity of stabilizer (DOTA/Acetic acid) was added and stirred well for 1 minute till the solution turned clear.


5. The pH of the bulk solution was adjusted to 5.5 by using 5N Sodium hydroxide solution.


6. The bulk solution was lyophilized after filling into vials.


Example 6


















Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
% w/w



















1.
Duloxetine Hydrochloride
30.0
3
31.40


2.
Mannitol
45.0
4.5
47.10


3.
EDTA
0.2
0.02
0.20


4.
Lipoid PE 18:0/18:0-PEG-
10.0
1.0
10.46



2000


5.
L-Histidine
Q.s to
Q.s to
0.34




pH 6.0
pH 6.0


6.
1% Glycine solution
Q.s to 1 mL
Q.s to 100%
10.46










Note: pH of the formulation: 5.5-6.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid PE 18:0/18:0-PEG-2000 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 7


















Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
% w/w



















1.
Duloxetine Hydrochloride
30.00
3
30.864


2.
Mannitol
45.00
4.5
46.296


3.
EDTA
0.20
0.02
0.2058


4.
Lipoid PE 18:0/18:0-PEG-
10.00
1.00
10.288



2000


5.
Di-sodium succinic acid
Q.s to
Q.s to
2.0576




pH 6.0
pH 6.0


6.
1% Glycine solution
Q.s to 1 mL
Q.s to 100%
10.288










Note: pH of the formulation: 5.5-6.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid PE 18:0/18:0-PEG-2000 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using disodium succinic acid.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 8
















Example 8A
Example 8 B
















Qty
Qty
Qty
Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
% w/w
(mg/mL)
% w/v
% w/w

















1.
Duloxetine
30.00
3.00
31.40
30.0
3.0
30.86



Hydrochloride


2.
Mannitol
45.00
4.50
47.10
45.0
4.50
46.29


3.
EDTA
0.20
0.02
0.20
0.20
0.02
0.205


4.
Soy lecithin
10.00
1.00
10.468
10.0
1.00
10.28



(Lipoid S 100)


5.
L-Histidine
0.32
0.03
0.34





6.
Disodium



2.000
0.20
2.057



Succinate


7.
1% Glycine
Q.s to
Q.s to
10.46
Q.s to
Q.s to
10.28



solution
1 mL
100%

1 mL
100%










Note: pH of the formulation: 5.5 to 6.5


Manufacturing Process


Example 8A Manufacturing Process:


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 8B Manufacturing Process:


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using disodium succinate.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


The formulation made as per the composition of 8A is tested for stability. The data at the end of 6 months is tabulated below. The data clearly shows that each individual impurity is less than 0.5% even at accelerated conditions after 6 months.









TABLE 7







Stability data of 8A formulation.


Duloxetine Hydrochloride Injection









Condition













Initial
6 M-2-8° C.
6 M-25° C.
6 M-30° C.
6 M-40° C.










Strength
30 mg/Vial

















1.
Description
White
White
White
White
Light Yellow




lyophilized
lyophilized
lyophilized
lyophilized
color




cake
cake
cake
cake



pH
6.26
6.07
5.99
5.93
5.26



Water Content
NA
0.4
0.9
0.5
1.3



(mg/vial)


2.
Assay (%)
104.7
104.3
100.6
101.5
102.9


3.
Impurity Name



Duloxetine Alcohol
0.00
ND
ND
ND
0.01



Duloxetine 4-
0.01
0.01
0.01
0.01
0.01



Napthyl isomer



Alpha Napthol
0.00
0.01
0.02
0.02
0.06



Duloxetine Beta
0.01
0.01
0.01
0.01
0.01



napthol-1-yl isomer


4.
Total Impurities
0.10
0.10
0.13
0.14
0.40



(%)









Example 9



















Qty
Qty
Qty
Qty


S. No
Ingredients
(mg/5 mL)
(mg/mL)
% w/v
% w/w




















1.
Duloxetine
30.00
6.00
0.60
8.54



Hydrochloride


2.
Pregabalin
75.0
15.0
1.50
21.35


3.
Mannitol
185
37
3.70
52.68


4.
EDTA
0.20
0.04
0.004
0.05


5.
Soy lecithin
10.0
2.00
0.20
2.84



(Lipoid S 100)


6.
L-Histidine
0.96
0.19
0.019
0.27


7.
1% Glycine
Q.s to
Q.s To
Q.s to
14.23



solution
5 mL
1 mL
100%










Note: pH of the formulation: 5.5-7.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of pregabalin and stirred well for 15 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.5±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 10


















Qty
Qty
Qty


S. No
Ingredients
(mg/1 mL)
% w/v
% w/w



















1.
Duloxetine
30.0
3.0
15.34



Hydrochloride


2.
Gabapentin
100.0
10.0
51.14


3.
Mannitol
45.00
4.50
23.01


4.
EDTA
0.20
0.02
0.10


5.
Soy lecithin
10.00
1.00
5.11



(Lipoid S 100)


6.
L-Histidine
0.32
0.033
0.16


7.
1% Glycine solution
Q.s to 1 mL
Q.s to 100%
5.11










Note: pH of the formulation: 5.5-7.0


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of gabapentin and stirred well for 15 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.5±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 11


















Example 11A

Example 11B



















Qty
Qty
Qty
Qty
Qty
Qty
Qty
Qty




(mg/
(mg/
%
%
(mg/
(mg/
%
%


S. No
Ingredients
20 mL)
mL)
w/v
w/w
20 mL)
mL)
w/v
w/w



















1.
Duloxetine
30.00
1.50
0.30
2.66
30.00
1.50
0.30
3.22



Hydrochloride


2.
Dexamethasone
8.00
0.40
0.08
0.711
12.00
0.60
0.12
1.29



sodium



phosphate


3.
Mannitol
875.00
43.75
4.37
77.74
875.00
43.75
4.37
94.10


4.
EDTA
0.20
0.01
0.002
0.017
0.20
0.01
0.002
0.021


5.
Soy lecithin
10.00
0.50
0.10
0.88
10.0
0.50
0.10
1.075



(Lipoid S 100)


6.
L-Histidine
2.36
0.118
0.011
0.20
2.59
0.12
0.012
0.27


7.
1% Glycine
Q.s to
Q.s. to
Q.s to
17.768
Q.s to
Q.s. to
Q.s to
3.22



solution
20 mL
1 mL
100%

10 mL
1 mL
100%










Note: pH of the formulation: 7.5-8.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of dexamethasone sodium phosphate and stirred well for 45 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 7.8±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 12



















Qty
Qty
Qty
Qty


S. No
Ingredients
(mg/25 mL)
(mg/mL)
% w/v
% w/w




















1.
Duloxetine
30.00
1.20
0.12
2.39



Hydrochloride


2.
Diclofenac
37.50
1.50
0.15
2.99



Sodium


3.
Mannitol
920.00
36.80
3.68
73.36


4.
EDTA
0.20
0.01
0.001
0.019


5.
Soy lecithin
10.00
0.40
0.04
0.79



(Lipoid S 100)


6.
L-Histidine
6.24
0.24
0.024
0.49


7.
1% Glycine
Q.s to
Q.s. to
Q.s to
19.936



solution
25 mL
1 mL
100%










Note: pH of the formulation: 5.5-7.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of Diclofenac Sodium and stirred well for 45 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.5±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 13



















Qty
Qty
Qty
Qty


S. No
Ingredients
(mg/50 mL)
(mg/mL)
% w/v
% w/w




















1.
Duloxetine
30.00
0.60
0.060
1.0375



Hydrochloride


2.
Paracetamol
500.00
10.00
1.000
17.291


3.
Mannitol
1835.00
36.70
3.670
63.46


4.
EDTA
0.20
0.00
0.000
0.0069


5.
Soy lecithin
10.00
0.20
0.020
0.346



(Lipoid S 100)


6.
L-Histidine
16.4
0.328
0.0328
0.567


7.
1% Glycine
Q.s to
Q.s. to
Q.s to 100%
17.29



solution
50 mL
1 mL










Note: pH of the formulation: 5.5-6.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid S 100 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of paracetamol and stirred well for 60 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 14


















Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
(w/w)



















1.
Duloxetine
30.00
3
15.343



Hydrochloride


2.
Lidocaine HCl
100.00
10
51.143


3.
Mannitol
45.00
4.5
23.015


4.
EDTA
0.20
0.02
0.1023


5.
Lipoid PE 18:0/
10.00
1.00
5.1144



18:0-PEG-2000


6.
L-Histidine
Q.s to pH 6.0
Q.s to pH 6.0
0.168


7.
1% Glycine
Q.s to 1 mL
Q.s to 100%
5.12



solution










Note: pH of the formulation: 5.5-6.5


Manufacturing Process


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid PE 18:0/18:0-PEG-2000 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of lidocaine hydrochloride and stirred well for 30 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 15


















Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
% w/w



















1.
Duloxetine
30.00
3
15.21



Hydrochloride


2.
Lidocaine HCl
100.0
10
50.71


3.
Mannitol
45.0
4.5
22.8


4.
EDTA
0.20
0.02
0.10


5.
Lipoid PE 18:0/
10.0
1.0
5.07



18:0-PEG-2000


6.
Di-sodium succinic
Q.s to pH 6.0
Q.s to pH 6.0
1.01



acid


7.
1% Glycine
Q.s to 1 mL
Q.s to 100%
5.07



solution










Note: pH of the formulation: 5.5-6.5


Manufacturing Procedure


1. Preparation of 1% Glycine solution: Required quantity of ultrapure water was taken in a stainless steel vessel to which desired quantity of Glycine was added to get 1% w/v solution.


2. Preparation of Bulk solution: 80% of glycine solution required was taken in a manufacturing vessel to which dispensed quantity of Lipoid PE 18:0/18:0-PEG-2000 was transferred and stirred for 15 minutes at 450 rpm to obtain a clear solution.


3. To the above solution dispensed quantity of duloxetine was added and stirred for 30 minutes at 400 rpm for obtaining a clear solution, followed by addition of Lidocaine hydrochloride and stirred well for 30 minutes at 400 rpm until a clear solution is obtained.


4. Dispensed quantity of Mannitol was added to the above solution and stirred for 30 minutes at 400 rpm to get a clear solution.


5. Required quantity of EDTA was transferred to the manufacturing vessel and stirred for 15 minutes at 400 rpm to get clear solution.


6. pH of the above bulk solution was adjusted to pH 6.0±0.1 using disodium succinic acid.


7. Final volume of the bulk solution was adjusted to desired level with remaining amount of 1% glycine solution.


8. The bulk solution was lyophilized after filling into vials.


Example 16


















Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
% w/w



















1.
Duloxetine
30.00
3.00
31.40



Hydrochloride


2.
Mannitol
45.00
4.50
47.10


3.
EDTA
0.20
0.02
0.20


4.
Egg lecithin
10.00
1.00
10.46



(Lipoid E80S)


5.
L-Histidine
0.32
0.03
0.34


6.
1% Glycine
Q.s to 1 mL
Q.s to 100%
10.46



solution









Manufacturing Process


1. Preparation of 1% glycine solution: Required quantity of glycine was dissolved in required quantity of water.


2. Preparation of Bulk solution: 80% of glycine solution required for the batch was taken in a manufacturing vessel to which required quantity of Lipoid E80S was transferred and stirred to obtain a clear solution.


3. To the above solution required quantity of duloxetine was added and stirred to get clear solution.


4. Required quantity of Mannitol was added to the above solution and stirred to get a clear solution.


5. Required quantity of EDTA was transferred to the above solution and stirred to get clear solution.


6. pH of the above bulk solution adjusted to pH 6.0±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted with remaining amount of 1% glycine solution.


8. The bulk solution was filtered and filled into vials and were then partially stoppered with single slotted lyo stopper and subjected for lyophilisation.


9. After lyophilisation the vials were stoppered completely under vacuum and were sealed with aluminium tear off seals after unloading.


Example 17


















Qty
Qty
Qty


S. No
Ingredients
(mg/mL)
% w/v
% w/w



















1.
Duloxetine
30.00
3.00
31.40



Hydrochloride


2.
Mannitol
45.00
4.50
47.10


3.
EDTA
0.20
0.02
0.20


4.
HPBCD
10.00
1.00
10.46



(Hydroxypropyl



Beta cyclodextrin)


5.
L-Histidine
0.32
0.03
0.34


6.
1% Glycine
Q.s to 1 mL
Q.s to 100%
10.46



solution









Manufacturing Process


1. Preparation of 1% glycine Solution: Required quantity of glycine was dissolved in required quantity of water.


2. Preparation of Bulk Solution: 80% of glycine solution required for the batch was taken in a manufacturing vessel to which required quantity of HPBCD was transferred and stirred obtain a clear solution.


3. To the above solution required quantity of duloxetine was added and stirred to get clear solution.


4. Required quantity of Mannitol was added to the above solution and stirred to get a clear solution.


5. Required quantity of EDTA was transferred to the above solution and stirred to get clear solution.


6. pH of the above bulk solution adjusted to pH 6.0±0.1 using L-histidine.


7. Final volume of the bulk solution was adjusted with remaining amount of 1% glycine solution.


8. The bulk solution was filtered and filled into vials and were then partially stoppered with single slotted lyo stopper and subjected for lyophilisation.


9. After lyophilisation the vials were stoppered completely under vacuum and were sealed with aluminium tear off seals after unloading.


Example 18: Compositions of Duloxetine API Solution Prepared in Phosphate Buffer pH 6.4 (Used as Control in the Study)


















Qty
Qty
Qty


S. No
Material name
(mg/mL)
% w/v
% w/w



















1.
Duloxetine
30.00
3.00
2.94



Hydrochloride


2.
Phosphate Buffer
Q.s to 1 mL
Q.s to 100%
97.06



pH 6.8









Manufacturing Process


1. 80% of Phosphate buffer pH 6.8 required for the batch was taken in a SS vessel.


2. Required quantity of Duloxetine API was dispensed and transferred to the above vessel and dissolved with stirring for 10 minutes at 300 rpm.


3. Ensuring the clarity of the solution the volume was adjusted with remaining amount of Phosphate buffer.

Claims
  • 1. A parenteral formulation comprising lyophilized duloxetine or a pharmaceutically acceptable salt thereof, optionally together with one or more pharmaceutically acceptable excipients.
  • 2. The formulation of claim 1, wherein the moisture content of the lyophilized cake is less than 5% w/w.
  • 3. The formulation of claim 1, wherein the content of Duloxetine Alcohol, Duloxetine Napthol 4-yl isomer, Alpha Napthol and Duloxetine Beta napthol-1-yl isomer individually is less than 0.5% w/w.
  • 4. The formulation of claim 1, wherein the pharmaceutically acceptable excipients are selected from the group comprising bulking agents, aqueous vehicle, stabilizers, and surfactants.
  • 5. The formulation of claim 4, wherein the bulking agents are selected from mannitol, dextrose, cyclodextrin, sodium chloride and sorbitol.
  • 6. The formulation of claim 4, wherein the aqueous vehicle is selected from one or more buffers selected from the group comprising acetate buffer, phosphate buffer, aspartic acid and boric acid buffer, citrate buffer and glycine buffer, histidine buffer, succinate buffer, alanine buffer, valine buffer, lactic acid buffer.
  • 7. The formulation of claim 4, wherein the surfactant is selected from the group comprising lecithin, soya lecithin, egg lecithin, PEG-PE and phosphatidyl choline.
  • 8. A kit comprising (i) a vial comprising lyophilized duloxetine, optionally with pharmaceutically acceptable excipients and (ii) a vial comprising a diluent
  • 9. The kit of claim 8 wherein the diluent is selected from the group comprising water for injection, dextrose solution, normal saline, mannitol solution, dextrose normal saline solution, half saline solution.
  • 10. The kit of claim 8, wherein the pH of the reconstituted solution is between 4-8.
Priority Claims (1)
Number Date Country Kind
201941047735 Nov 2019 IN national
PCT Information
Filing Document Filing Date Country Kind
PCT/IB2020/061263 11/30/2020 WO