1. Technical Field
Present innovation is related to a sustained/controlled release formulation for solid pharmaceuticals, primarily designed for oral administration. The innovation is referred to a two-component system which ensures sustained release of the active substance, therefore administration of a single dosage unit once or twice daily.
2. Description of the Background of the Invention
The advantages of drug delivery in a controlled manner have been described in the literature (e.g. Khan, M. Z. I, Drug Dev. Ind. Pharm., 21 (1995) 1037-1070). Most importantly, controlled/sustained release dosage forms allow the drug(s) to be released in optimum amounts, minimising unwanted side effects over a prolonged period, thus obviating the need for multiple administration. Not surprisingly, controlled/sustained release dosage forms have now become the state of the art in the area of drug delivery technology. Large number of drug delivery systems which would release a sufficient amount of drug(s) for the initial bioavailability for faster action, followed by a controlled/sustained release for prolonged/continuous action over time have been described, e.g:
One of the major problems associated with controlled/sustained release dosage forms described in these and other patents and in the scientific literature in general is the possibility of dose dumping. Most of these systems do not offer a mechanism of minimising the risk of dose dumping which can seriously affect patients' safety and tolerability. The present invention offers therapeutic effect over prolonged period of time with minimised risk of dose dumping due to dual mechanism of controlling the release of the active agent from the dosage form. By changing the ratio of two components comprised in the present system, an ideal release rate with maximum relief for the patient can easily be achieved, with minimised risk of side effects and/or toxicity.
Also, most controlled/sustained release drug delivery systems require sophisticated technology, which is not available in standard facilities. In contrast, the manufacturing process and technology described in this invention involves standard technologies and equipment commonly used for manufacture of conventional dosage forms.
Biopharmaceutics Classification Scheme (BCS) categorises drug substances into four basic groups according to their solubility and capability to penetrate into plasma through the gastrointestinal wall (e.g. Dressman, J. B et al, Pharm. Res., 15(1) (1998) 11-22). Drug substances belonging to Class I are highly soluble and highly permeable. Drug substances belonging to Class II are poorly soluble and highly permeable. Drug substances belonging to Class III are highly soluble and poorly permeable, whereas substances belonging to Class IV are poorly soluble and poorly permeable drugs.
An object of the present invention is to provide an oral controlled/sustained release formulation with minimised risk of dose dumping and side effects, or, at least, to provide the public with a useful choice, independently of the solubility and permeability of the drug substances.
Accordingly, in the first aspect the present invention provides a solid controlled release oral dosage formulation, comprising two components wherein:
In another aspect, the present invention provides a method of preparation of a sustained release solid dosage form including two components wherein:
In a further aspect, the present invention provides the use of a sustained release solid dosage formulation including two components wherein:
In a still further aspect, the present invention provides a method of minimising dose dumping comprising administering to a patient in need thereof a sustained release solid dosage formulation including two components wherein:
In a yet further aspect, the present invention provides a use, in the preparation of a sustained release solid dosage form for a sustained release of a pharmaceutically active agent in a patient in need thereof, of:
In another aspect, the present invention provides a process for the production of a sustained release solid dosage formulation, including combining:
Although the invention is broadly defined above, it is not limited thereto and, also, includes embodiments of which the following description provides examples.
Dissolution testing was carried out by using USP apparatus I at 150 rpm. For the first 30 minutes the release profile was tested in diluted hydrochloric acid (pH 2.5) and then in mixed phosphate buffer (pH 6.8) for 8 hours. The data represent mean values obtained from 6 tablets. The pharmaceutically active agent, torasemide, contained in the dosage form is highly soluble and highly permeable (Class I, according to Biopharmaceutics Classification System).
As defined above, the present invention relates to a novel solid sustained/controlled release oral dosage formulation.
The formulation of the invention comprises a two-component system. The first component comprises an active pharmaceutical agent in combination with a water-insoluble, but water-permeable polymer.
The first component is preferably in the form of granules and is capable of sustaining the release of the active agent over a prolonged period of time, depending on the amount of polymer, either if the shape of the dosage form remains intact or even if it is disintegrated into small pieces.
Preferably, the water-insoluble, but water-permeable polymeric material comprises one or more methacrylic acid copolymers, ethylcellulose or mixture thereof and others with similar properties. Conveniently, the water-insoluble, but water-permeable polymeric material is presented in an amount within the range of from about 2-90% (w/w) and/or in the proportion to the active substance from (1:10) to (10:1).
The second component of the system contains an active pharmaceutical agent, untreated with the water-insoluble polymer, and available for substantially immediate release, depending on the physico-chemical properties of the active agent.
The second component of the formulation also contains a hydrophobic, preferably a lipid or lipidic material. More preferably, the hydrophobic material is selected from the group of glycerine fatty acid esters, vegetable oils and their derivatives, higher fatty acids, their metal salts and other material with similar properties. It will be appreciated by art-skilled workers that the release rate of the active agent in the second component is controlled by the amount of the hydrophobic material presented in the formulation in an amount within the range of from about 2-80% (w/w) and/or in the proportion to the active substance from (1:10) to (10:1). The second component is conveniently not granulated, but can, also, be in the form of granules in which the hydrophobic material (e.g. lipid) can be added in melted state, if required.
Without wishing to be bound by theory, it is believed that the risk of dose dumping in the present invention is minimised due to dual mechanism of controlling/sustaining the release process due to the dual component system. In the case of an oral dosage formulation of the invention, the main role of the hydrophobic (second) component of the system is to control the penetration rate of the gastrointestinal fluid into the dosage form and, thereby, to control the release of the drug available in untreated form (in the second component). As a result of a control of gastrointestinal fluid penetration rate, the hydrophobic component also, indirectly, controls the release of the drug available inside the granules. In other words, the release of the drug available in the granules (first component) is controlled by both the water-insoluble, but water-permeable polymer and, also, the hydrophobic material in the second component. Therefore, if the system (the dosage form) fails accidentally (e.g. as a result of food intake) or naturally (due to gastrointestinal motility), the risk of dose dumping is minimised because the first component would not release the drug due to control by the water-insoluble, but water-permeable polymer.
Preferably, the pharmaceutically active agent of the second component is the same as that of the first component. The pharmaceutically active agent may also comprise a mixture of agents. Having the same active pharmaceutical agent in the first and second components affords a formulation in which part of the active agent is available for substantially immediate release (depending on the quantity of hydrophobic material added), and part of the active agent will be released over a prolonged period of time. However, formulations in which the first and second components comprise different pharmaceutically active agents are also contemplated and are by no means excluded.
The first component may be prepared by combining the pharmaceutically active agent with a polymeric substance that is insoluble in water, but permeable to water. As a result, the release rate of the active agent from the first component can be controlled by adjusting the amount of the polymer, depending on the physico-chemical characteristics of the active agent. In addition, standard pharmaceutical excipients can be used to obtain granules with appropriate compressibility for tabletting.
Preferably, the first component is in granular form and two components are in the admixture.
Optionally, the first component may also contain one or more pharmaceutically acceptable excipients. Examples of suitable excipients include (but are not limited to) lactose and/or microcrystalline cellulose, croscarmellose sodium, starch and/or starch derivatives. Such excipients can also be used to enhance the permeability of water to the granules, and, consequently, enhance the release rate of the drug if required. Lactose and microcrystalline cellulose are examples of suitable filler excipients.
Generally, the second component of the system contains the pharmaceutically active agent available for substantially immediate release. However, the release process can be controlled by the amount of hydrophobic material in the second component.
Optionally, the second component may also contain one or more pharmaceutically acceptable excipients and/or tabletting aids. Fillers, glidants, lubricants and mixtures thereof may also be provided in the second component. Non-limiting examples include calcium hydrogen phosphate and hydrogenated vegetable oil NF, Type I. Conveniently, these may be mixed with talc and magnesium stearate.
Preferably, the dosage form is a tablet or capsule. In a particularly preferred embodiment, the dosage formulation is an oral dosage formulation. However, sustained release profiles afforded by a dosage formulation of the invention make it suitable to be adapted to many different types of dosage forms. Non-limiting examples of other dosage forms contemplated include suppositories and subcutaneous implants.
Controlled release oral dosage formulations of the invention may be in the form of tablet compressed from a blend of the two components, and, also:
If the desired pharmaceutical dosage form is a tablet, the granules (the first component) are mixed with the second component which comprises: the active agent, a hydrophobic material (preferably a lipid or lipidic material such as fatty acids or their esters) and some tabletting materials (e.g. antiadherents, glidants, lubricants), and then compressed into tablets.
A film coating may optionally be added to the dosage formulation. The coating layer can be either non-functional (for example to give an elegant appearance, identification or colour) or functional, such as enteric coating, or to incorporate the active in the coating layer for rapid release for immediate action (instant release). The film coating may conveniently comprise one or more film formers, plasticisers, colouring agents, and mixture thereof.
The water insoluble polymeric substances suitable for granulation and/or control of the release of the drug from the granules can be chosen from, but not restricted to, the range of methacrylic acid copolymers, such as Eudragit RS or Eudragit RL (either in the form of a powder or aqueous suspension or a combination of both forms), Eudragit NE 40D or Eudragit NE 30D, or a combination of both polymers in appropriate amounts and forms (powder/suspension).
The pharmaceutically active agent is generally an agent required to be administered by sustained release. Examples of such agents include agents with toxicity in high doses and agents to be administered over an extended period of time.
The controlled release formulation of the present invention may contain active agent(s) from a variety of therapeutically active groups, such as, for example, ace-inhibitors, alkaloids, antacids, analgesics, anabolic agents, anti-anginal drugs, anti-allergy agents, anti-arrhytmia agents, antiasthmatics, antibiotics, anticholesterlolemics, anticonvulsants, anticoagulants, anti-emetics, antihistamines, antihypertensives, anti-infectives, nonsteroidal anti-inflammatory drugs (NSAIDs), steroidal anti-inflammatory drugs, central nervous system (CNS) stimulators, CNS depressants, antimigraine agents, contraceptives, cough suppresants, deodorants, dermatological agents, diuretics, fungicides, gastro-intestinal agents, vitamins, minerals polypeptides, prostaglandins, respiratory stimulans, uterine relaxants, and many others already known, as well as the new drugs.
In the case of drugs that are, according to Biopharmaceutics Classification System (BCS), highly soluble such as, for example, torasemide, venlafaxine in the form of venlafaxine hydrochloride or other salts, gabapentin, pravastatin sodium, ranitidine in the form of ranitidine hydrochloride or other salts, and others, well known and new drugs, the active ingredient contained in the second component (non-granulated form) is preferably in untreated form as a pure substance. However, in the case of drugs that are, according to BSC, poorly soluble, such as, for example, temazepam, diazepam, oxazepam, nifedipine, ibuprofen, loratadine, and others, well known and new drugs, the active ingredient contained in the second component (non-granulated form) is either in untreated form as a pure substance, or, optionally, in the form of solid dispersion in a carrier. Furthermore, the substance may be blended with pharmaceutical excipients suitable for further processing (tabletting or capsuling).
The carrier of the solid dispersion may be selected from a wide range of polymers (e.g. various types of polyethylene glycols) or other standard pharmaceutical excipients, such as, for example, polyvinyl pyrrolidone (povidones, Kollidon VA 64) and others.
In addition, solubility enhancers, such as substances capable of creating a microenvironment with optimum pH solubilization of the drug, can be included in the second component. The qualities and quantities of excipients can be determined on the basis of in-vitro experiments according to the desired release profile(s) of the drug(s).
The hydrophobic material used to control the release process from the second component (non-granulated form) is preferably chosen from a range of lipids or lipidic material, such as hydrogenated vegetable oils, pharmaceutical fats, fatty acids, glycerides, waxes and others.
The release kinetics of the active agent from the dosage formulation useful in the present invention may be effected by dual mechanism of action:
Without wishing to be bound by theory, having two completely different microenvironments with two completely different release retardant mechanisms provides a very effective mechanism for controlling the overall release of pharmaceutically active agent from the formulation.
Furthermore, adjusting the proportion of the active agent in the first and second components can control the release of the active agent.
The invention will now be described in more details with reference to the following non-limiting examples.
Tablets containing part of diclofenac sodium in granulated form using a methacrylic acid copolymer as the binder, and the remaining diclofenac sodium in non-granulated form mixed with a lipid.
Preparation of Granules Which Constitute the Continued Prolonged/Delayed Release Portion of the Tablets
Granules were prepared from a mixture of diclofenac sodium with microcrystalline cellulose, lactose and Eudragit RS as a binder, used in powder form and/or in the form of an aqueous suspension. Wet granules were dried in a fluid-bed dryer and then milled through a 20 mesh (0.8 mm) screen to obtain appropriate size distribution of the granules suitable for compressing.
Preparation of the Finished Tablets
Granules and the remaining part of the active drug, diclofenac sodium, lipid component, calcium hydrogenphosphate, hydrogenated vegetable oil NF Type I and talc were screened through a 20 mesh sieve and tumble mixed for 5 minutes. Magnesium stearate, screened through a 30 mesh (0.6 mm) sieve was then added to the final blend and mixed for another 5 minutes. The final blend was compressed into tablets. Tablets were coated with the aqueous suspension of methylhydroxypropylcellulose, polysorbatum, sodium lauryl sulfate, talc and pigments such as titanium dioxide as well as iron oxides red and yellow.
Granules and tablets were prepared in the same way as described in the Example 1.
Granules and tablets were prepared in the same way as described in the Example 1.
Preparation of Granules Which Constitute the Continued Prolonged/Delayed Release Portion of the Tablets
Granules were prepared from a mixture of diclofenac sodium with or without microcrystalline cellulose and lactose, with Eudragit RS as a binder, used in powder form and/or in the form of an aqueous suspension. Wet granules were dried in a fluid-bed dryer and then milled through a 20 mesh (0.8 mm) screen to obtain appropriate size distribution of the granules suitable for compressing.
Preparation of the Finished Tablets
Granules and the remaining part of the active drug, diclofenac sodium, lipid component, with or without calcium hydrogenphosphate and hydrogenated vegetable oil NF Type I, and with talc were screened through a 20 mesh sieve and tumble mixed for 5 minutes. Magnesium stearate, screened through a 30 mesh (0.6 mm) sieve was then added to the final blend and mixed for another 5 minutes. The final blend was compressed into tablets. Tablets were coated with the aqueous suspension of methylhydroxypropylcellulose, polysorbatum, sodium lauryl sulfate, talc and pigments such as titanium dioxide as well as iron oxides red and yellow.
Tablets containing part of torasemide in granulated form using a methacrylic acid copolymer as the binder, and the remaining torasemide in non-granulated form mixed with a lipid.
Preparation of Granules Which Constitute the Continued Prolonged/Delayed Release Portion of the Tablets
Granules were prepared from a mixture of torasemide with Eudragit RS as a binder, used in powder form and/or in the form of an aqueous suspension. Wet granules were dried in a fluid-bed dryer and then milled through a 20 mesh (0.8 mm) screen to obtain appropriate size distribution of the granules suitable for compressing.
Preparation of the Finished Tablets
Granules and the remaining part of the active drug, torasemide, lipid component and talc were screened through a 20 mesh sieve and tumble mixed for 5 minutes. Magnesium stearate, screened through a 30 mesh (0.6 mm) sieve was then added to the final blend and mixed for another 5 minutes. The final blend was compressed into tablets.
Granules and tablets were prepared in the same way as described in the Example 5.
Granules and tablets were prepared in the same way as described in the Example 5.
Tablets containing part of ranitidine in the form of ranitidine hydrochloride in granulated form using a methacrylic acid copolymer as the binder, and the remaining ranitidine in the form of ranitidine hydrochloride in non-granulated form mixed with a lipid.
Preparation of Granules Which Constitute the Continued Prolonged/Delayed Release Portion of the Tablets
Granules were prepared from a mixture of ranitidine in the form of ranitidine hydrochloride with Eudragit RS as a binder, used in powder form and/or in the form of an aqueous suspension. Wet granules were dried in a fluid-bed dryer and then milled through a 20 mesh (0.8 mm) screen to obtain appropriate size distribution of the granules suitable for compressing.
Preparation of the Finished Tablets
Granules and the remaining part of the active drug, ranitidine in the form of ranitidine hydrochloride, lipid component, hydrogenated vegetable oil NF, Type I and talc were screened through a 20 mesh sieve and tumble mixed for 5 minutes. Magnesium stearate, screened through a 30 mesh (0.6 mm) sieve was then added to the final blend and mixed for another 5 minutes. The final blend was compressed into tablets.
Granules and tablets were prepared in the same way as described in the Example 8.
Granules and tablets were prepared in the same way as described in the Example 8.
It is envisaged that the dosage forms of the present invention will enable controlled delivery of a range of drugs to be provided in a way that maximises therapeutic benefit and patient compliance, while minimising side effects of the drug.
Although the invention has been described with reference to a particular embodiments, it will be appreciated by those people skilled in the art that various alterations and modifications can be made without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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P20020124A | Feb 2002 | HR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/HR02/00018 | 3/27/2002 | WO |