Pharmaceutical administration form for peptides, process for its preparation, and use

Abstract

The invention relates to pharmaceutical compositions suitable for parenteral administration comprising, peptides in the form of acetate, gluconate, glucuronate, lactate, citrate, ascorbate, benzoate or phosphate salts in dissolved or dispersed form and at least one of the acids for forming the salts in free acid form.

Description

The invention relates to novel galenic forms for the parenteral administration of peptides prone to aggregation, in particular of LHRH analogues or LHRH antagonists and agonists, and processes for their preparation, and use.

EP 0 299 402 discloses the use of pharmaceutically active decapeptides such as SB-030, SB-075 (cetrorelix) and SB-088 in the form of their pharmaceutically acceptable, non-toxic acid addition salts such as hydrochlorides, hydrobromides, sulphates, phosphates, fumarates, gluconates, tannates, maleates, acetates, citrates, benzoates, succinates, alginates, pamoates, ascorbates and tartrates etc.

JP 06321800-A furthermore discloses a lyophilized peptide or protein preparation which contains gluconate salts as stabilizers. In one example, the solution contains 2.5% of magnesium gluconate, the active compounds described being, inter alia, vasopressin, LHRH and insulin.

It is known from the literature, inter alia from Powell, M. F., Pharmaceutical Research, 1258-1263(8) 1991; Dathe M. Int. J. Peptide Protein Res. 344-349(36) 1990, and Szejtli, J. Pharmaceutical Technology International 16-22, 1991, that oligopeptides, namely particularly those having a terminal acid amide function, are prone to gel formation.

EP 0 611 572 describes a preparation process for a lyophilizate of a peptide having 3-15 amino acids, according to which 100-10,000 parts by weight of the peptide are dissolved in acetic acid and treated with bulking agents such as mannitol, and then lyophilized in order to obtain a sterile-filtered lyophilizate of the peptide and to avoid gel formation.

DE A 195 42 873 describes pharmaceutical administration forms of complicated composition in the form of microparticles, according to which an ABA triblock copolymer is used whose A block is a polymer of milk [sic] and glycolic acid and whose B polymer is a polyethylene glycol chain, together with an additive from the group consisting of the serum proteins, polyamino acids, cyclodextrins, cyclodextrin derivatives, saccharides, amino sugars, amino acids, detergents or carboxylic acids and mixtures of these substances. After inclusion of small or aggregation-sensitive amounts of polypeptide, the microparticles described should also release the polypeptide continuously over a relatively long period.

DD 141 996 describes the preparation of pharmaceutical forms of native LHRH which are stable over a relatively long period and comply with the requirements for a parenterally administerable preparation. The key point here is the improvement in the shelf life of these preparations (page 2, lines 19-23). No statement is made about the filterability of the solutions. Moreover, to improve the shelf life buffer substances (also acetic acid) are also employed to establish a pH range of pH 3.5-6.5. The problem of preparing sterile lyophilizates from gel-forming peptide salts is not solved there.

EP 0 175 506 treats an aqueous solution of the peptide with 1N acetic acid and then lyophilizes it in order to obtain the acetate salt of the peptide. The subject of this application is thus the synthesis of the peptide salts.

However, it has been shown that in the case of the known acetate salts of the peptides prone to aggregation, such as the LHRH antagonists, the preparation of sterile solutions for parenteral administration by means of filtration, especially at high concentrations, is indeed possible, but aggregates can form shortly before injection after the dissolution of the lyophilizate. The aggregates then lead to a concentration-dependent lowering of the bioavailability from a peptide concentration of 0.5 mg/ml.

The problem mentioned occurs not only with injection solutions which are administered for the purpose of rapid release of active compound, but is also observed with injection preparations which exhibit delayed release. Thus peptides, incorporated in matrices which should control the release of active compound, can have an undesirably low release on account of their proneness to aggregation. Thus the bioavailability is also lowered here.

Starting from the fact that the preferred administration of pharmaceutically active peptides such as LHRH agonists and antagonists, for example antarelix and cetrorelix, is the parenteral pharmaceutical form, a need exists for the provision of stable injection preparations having acceptable bioavailability, which can be conveniently prepared, sterile-filtered and formulated. This applies in particular to injection preparations in the form of reconstituted lyophilizates of soluble peptide salts and to microparticles, microcapsules or implants.

This is all the more of importance in consideration of the varied areas of use of the LHRH antagonists, which are becoming more and more known.

A wider selection of parenterally, in particular subcutaneously, injectable, stable peptide solutions is desirable in view of the rapidly growing indication areas of this class of substance.

Pharmaceutical administration forms suitable for parenteral administration, which contain peptides prone to aggregation in dissolved or dispersed form, have now been developed which are distinguished in that the peptides are present in the form of their acetate, gluconate, glucuronate, lactate, citrates, ascorbate, benzoate or phosphate salts and that these administration forms can additionally contain one of the just-mentioned acids as free acids, and, if appropriate, further additives and excipients from the class consisting of the acids, surface-active substances, polymers, lipids or sugars.

These pharmaceutical administration forms can be present in dissolved or dispersed form in water or in aqueous solvent mixtures.

According to a further embodiment of the invention, the pharmaceutical administration forms can also be present in dissolved or dispersed form in a physiologically tolerable oil, preferably medium-chain triglycerides (neutral oils, Miglyol®) or castor oil, sesame oil, cottonseed oil, maize oil, peanut oil, olive oil or in mixtures of such oils.

The peptides employed are the LHRH antagonists antide, A-75998, ganirelix and Nal-Glu antagonist, but in particular cetrorelix, antarelix and the antagonists according to the U.S. Pat. No. 5,942,493 and DE 19911771.3.

Acids employed in the excipient function are gluconic acid, glucuronic acid, galacturonic acid, glucaric acid, citric acid, ascorbic acid and amino acids.

It is thus possible to suppress the aggregation of the peptide and thus to fulfil the requirements for a preparation having good bioavailability, and thus to enrich the pharmaceutical wealth and to do so with efficient galenic technology.

It has further surprisingly been found that by the addition of gluconic, glucuronic, citric, lactic or ascorbic acid, the stability of various cetrorelix salts is moreover considerably improved.

According to the invention, the preparation and formulation of sterile-filtered, stable preparations is thus possible without problems.

It is additionally advantageous to add suitable excipients. These excipients can be acids, surface-active substances, polymers, lipids or sugars. Examples of acids are gluconic acid, glucuronic acid, galacturonic acid, glucaric acid, lactic and citric acid, ascorbic acid and amino acids. Surface-active substances employed can be polyethylene glycol 12-(hydroxy)stearate (Solutol®), polyoxyethylene ricinoleate (Cremophor®), polysorbates, poloxamers, phospholipids, lecithins or benzalkonium chloride. Suitable polymers are albumins, polyethylene glycols, cellulose derivatives, starch derivatives or polyvinylpyrrolidone. Examples of sugars are cyclodextrins and cyclodextrin derivatives. ‘Chaotropic’ substances such as urea can also serve as additives and/or excipients.

The area of use of the preparations according to the invention is in particular in the prevention and therapy of all sex hormone-dependent conditions and diseases which can be influenced by LHRH analogues, i.e. LHRH agonists and LHRH antagonists. Those to be emphasized here are:

benign prostate hyperplasia, carcinoma of the prostate, precocious puberty, hirsutism, endometrial hyperplasia and its accompanying symptoms, endometrial carcinoma, in-vitro fertilization (IVF/COS/ART), contraception, premenstrual syndrome (PMS), uterine myomatosis, breast cancer, tubal obstruction (PTO), ovarian cancer, carcinoma of the uterus. The following substances are particularly preferred as LHRH antagonists for the composition according to the invention:cetrorelix, antarelix, antide, A-75998, ganirelix, the Nal-Glu antagonist, and LHRH antagonists according to the U.S. Pat No. 5,942,493 and DE 19911771.3.

The LHRH antagonists according to the patents U.S. Pat. No. 5,942,493 and DE 19911771.3 are compounds of the following general formulas I, V and VII and the salts thereof with pharmaceutically acceptable acids

in which n is the number 3 or 4, R¹ is an alkyl group, an alkyloxy group, an aryl group, a heteroaryl group, an aralkyl group, a heteroaralkyl group, an aralkyloxy group or a heteroaralkyloxy group, in each case unsubstituted or substituted, R² and R³ independently of one another are each a hydrogen atom, an alkyl group, an aralkyl group or a heteroaralkyl group, in each case unsubstituted or substituted, where the substitution can in turn consist of an aryl group or heteroaryl group, or —NR²R³ is an amino acid group, and R⁴ is a group having the formula (II)—(CH₂)_p—CO—NR⁵R⁶  (II)in which p is an integer from 1 to 4, R⁵ is hydrogen or an alkyl group and R⁶ is an unsubstituted or substituted aryl or heteroararyl group,

• • or R⁴ is a ring of the general formula (III)

in which q is the number 1 or 2, R⁷ is a hydrogen atom or an alkyl group, R⁸ is a hydrogen atom or an alkyl group and X is an oxygen or sulphur atom, where the aromatic or heteroaromatic radicals can be partially or completely hydrogenated and chiral carbon atoms can have the R- or S-configuration, and its salts with pharmaceutically acceptable acids;Ac-D-Nal(2)¹-D-(pCl)Phe²-D-Pal(3)³-Ser⁴-Tyr⁵-D-Xxx⁶-Leu⁷-Arg⁸-Pro⁹-D-Ala¹⁰-NH₂  (V)in which D-Xxx is an amino acid group of the general formula (VI)

in which n is the number 3 or 4, R⁴ is a group of the formula (II)

in which p is an integer from 1 to 4, R⁵ is hydrogen or an alkyl group and R⁶ is an unsubstituted or substituted aryl group or heteroaryl group,or R⁴ is a ring of the general formula (III)

in which q is the number 1 or 2, R⁷ is a hydrogen atom or an alkyl group, R⁸ is a hydrogen atom or an alkyl group and X is an oxygen or sulphur atom, and its salts with pharmaceutically acceptable acids; andA-Xxx¹-Xxx²-Xxx³-Xxx⁴-Xxx⁵-Xxx⁶-Xxx⁷-Xxx⁸-Xxx⁹-Xxx¹⁰-NH₂  (VII)in whichA is an acetyl or a 3-(4-fluorophenyl)propionyl group,Xxx¹ is D-Nal(1) or D-Nal(2),Xxx²-Xxx³ is D-Cpa-D-Pal(3) or a single bond,Xxx⁴ is Ser,Xxx⁵ N-Me-Tyr,Xxx⁶ is D-Cit, D-Hci or a D-amino acid group of the general formula (VIII)

in which n is the number 3 or 4, where R¹¹ is a group having the general formula (IX)—(CH₂)—CO—NR¹²R¹³  (IX)where p is an integer from 1 to 4, R¹² is hydrogen or an alkyl group and R¹³ is an unsubstituted or substituted aryl group or heteroaryl group, or R¹¹ is a 3-amino-1,2,4-triazole-5-carbonyl group or R¹¹ is a ring of the general formula (X)

in which q is the number 1 or 2, R¹⁴ is a hydrogen atom or an alkyl group R¹⁵ is a hydrogen atom or an alkyl group and X is an oxygen or sulphur atom,Xxx⁷ is Leu or Nle,Xxx⁸ is Arg or Lys(iPr),Xxx⁹ is Pro andXxx¹⁰ is Ala or Sar,and their salts with pharmaceutically acceptable acids.

EXAMPLE 1

By means of polarization microscopy, aggregation investigations were carried out on solutions of various cetrorelix salts without or with addition of excipients.

In the polarization light microscope with crossed polarizers, aggregated peptide solutions show images which are very similar to those of liquid-crystalline structures. In contrast to this, aggregate-free peptide solutions produce no such effects.

TABLE 1
Influence of a gluconic acid addition on the
aggregation behaviour of cetrorelix acetate solutions.
		Gluconic acid
	Concentration	in the
	of cetrorelix	reconstitution		Days without
	acetate, mg/ml	medium, %:	pH	aggregation
	2.5	0	4.7	1
	2.5	0.0071	4.5	2
	2.5	0.071	3.7	2
	2.5	0.71	3.1	12

Thus the addition of gluconic acid causes an improvement in the stability of cetrorelix acetate solutions by delaying or preventing aggregation.

Further experiments concentrated on cetrorelix gluconate without or with addition of gluconic acid. The most important results are summarized in Table 2.

TABLE 2
Aggregation behaviour of various solutions
which were prepared from cetrorelix gluconate bulk material.
	Gluconic acid addition:
Concentration	Yes		No
of		Days		Days
cetrorelix,		without		without
mg/ml	pH	aggregation	pH	aggregation
2.5	3.0	>30
5	3.6	4	4.8	1
5	3.8	4	4.7	1
7.5	3.4	1	4.7	0
7.5	3.7	1	4.8	0

Cetrorelix gluconate thus offers advantages in comparison with the acetate salt. The addition of gluconic acid increases the shelf life of cetrorelix gluconate solutions.

Moreover, the stabilizing influence of glucuronic acid on cetrorelix acetate solutions and, as a further salt, also cetrorelix glucuronate, was tested for its aggregation behaviour. The results are summarized in Table 3.

TABLE 3
Aggregation behaviour of variously
concentrated solutions of cetrorelix acetate and
cetrorelix glucuronate without or with addition of
glucuronic acid.
	Glucuronic acid addition:
	Concentration	Yes	No
	of		Days		Days
	cetrotrelix,		without		without
Salt form	mg/ml	pH	aggregation	pH	aggregation
Acetate	2.5	3.0	>21	4.7	0
Acetate	5	3.0	0
Glucuronate	2.5	2.9	>30	4.5	3
Glucuronate	5	2.7	>30	4.6	0

Also, by the replacement of the acetate salt by a glucuronate salt, significant improvements can be achieved with respect to the aggregation stability of cetrorelix similarly to with the gluconate salt. By the addition of glucuronic acid to cetrorelix glucuronate solutions, the aggregation stability of these solutions can be even further improved.

TABLE 4
Aggregation-free duration in days of
cetrorelix acetate solutions after addition of 10% of
α-cyclodextrin, 20% of hydroxypropyl-β-cyclodextrin or
20% of γ-cyclodextrin.
Concentra-
tion of
cetrorelix
acetate,	α-Cyclo-	Hydroxypropyl-
mg/ml	dextrin	β-cyclodextrin	γ-Cyclodextrin
2.5	7	24	98 + (168, 182, 189)
5	0	7	31 + (140, 147, 182)
7.5	0	10	5 + (20, 20, 20)
10	0	2	2 + (4, 4, 4)
15		0	0

By the addition of hydroxypropyl-β-cyclodextrin and particularly of γ-cyclodextrin, the aggregation stability of cetrorelix acetate solutions can be significantly improved.

TABLE 5
Aggregation-free duration in days of 2.5 mg/ml
cetrorelix gluconate solutions after addition of
α-cyclodextrin, hydroxypropyl-β-cyclodextrin or
γ-cyclodextrin.
		Concentration of	Days without
	Cyclodextrin type	cyclodextrin, %	aggregation
	γ-Cyclodextrin	20	182
		6.8	126
	Hydroxypropyl-β-	20	189
	cyclodextrin	6.8	91
	α-Cyclodextrin	10	140
		5	1

By the addition of hydroxypropyl-β-cyclodextrin or of γ-cyclodextrin, the aggregation stability of cetrorelix gluconate solutions can also be significantly improved.

TABLE 6
Aggregation-free duration in days of
cetrorelix acetate solutions with addition of
polyvinylpyrrolidone (Kollidon ® 12 PF or 17 PF).
Concentration		Days without	Days without
of	Concentration	aggregation	aggregation
cetrorelix,	of Kollidon ®,	with Kollidon ®	with Kollidon ®
mg/ml	%	12 PF	17 PF
2.5	0	0	0
	5	1	2
	10	1	2
	15	77	63
	20	84	98
5	15	0	1
	20	0	1

Also, by the addition of various types of polyvinylpyrrolidone, the aggregation stability of cetrorelix acetate solutions can be significantly improved.

TABLE 7
Aggregation behaviour of cetrorelix acetate
solutions with addition of various excipients assessed
by means of polarization microscopy and according to
the optical appearance.
	Conc. of	Conc. of	Aggregation
Excipient	excipient	cetrorelix	(microscopy)	Appearance
Solutol ®	5.00%	2.5 mg/ml	yes, after	clear
HS 15			14 days	solution
	10.00%	2.5 mg/ml	≧112 days	clear
			without	solution
			aggregation
	20.00%	2.5 mg/ml	≧112 days	clear
			without	solution
			aggregation
Cremophor ®	5.00%	2.5 mg/ml	yes, after	clear
EL			10 days	solution
	10.00%	2.5 mg/ml	≧112 days	clear
			without	solution
			aggregation
	20.00%	2.5 mg/ml	≧112 days	clear
			without	solution
			aggregation
	20.00%	5 mg/ml	yes, after 1	clear,
			day	viscose
L-glutamic	0.80%	2.5 mg/ml	yes, after 2	clear
acid			days	solution,
				pH 3.8
Glucaric	2.50%	2.5 mg/ml	≧12 days	clear
acid			without	solution,
			aggregation	pH 2.5
Galact-	2.50%	2.5 mg/ml	≧12 days	clear
uronic			without	solution,
acid			aggregation	pH 2.6

EXAMPLE 2

Cetrorelix bulk material is dissolved in a concentration of 10 mg/ml in 30% strength acetic acid and diluted with an aqueous solution of the additives to a final concentration of 1 mg/ml of peptide in 3% acetic acid. This solution is then sterile-filtered and lyophilized (5 mg per vial).

After reconstitution of these lyophilizates, the solutions (2.5 mg/ml of cetrorelix) are investigated in the following tests for aggregate formation and release behaviour:

• • Polarization microscopy (pol. mic.): days without aggregation.
  • Filterability in %:
  • Cetrorelix solutions are prepared according to a standardized procedure and filtered through 0.22 μm or 0.45 μm filters by means of centrifugation. The concentration of cetrorelix in the filtrate is determined by HPLC and indicated as a % value, based on the starting concentration before filtration (filterability in %).
  • in-vitro release form (RRS, release in Ringer's solution):
  • % released after 1 h and after 6 h.
  • The in-vitro release behaviour is determined at 37° C. in a flow procedure using Ringer's solution as medium. The concentration measurement is carried out by HPLC. Cetrorelix samples, corresponding to 10 mg of cetrorelix base, are weighed into the flow cell, mixed with 4 ml of water and stirred for 10 min. After addition of 6 ml of Ringer's solution to the sample, Ringer's solution is pumped uniformly through the flow cell with a flow of 0.5 ml/min, with stirring.
  • Rat animal experiment: cetrorelix residual content in the muscle in % of the administered dose 168 h after injection.

Some prepared batches of cetrorelix acetate lyophilizate and the corresponding test results of 2.5 mg/ml cetrorelix acetate solutions prepared therefrom are shown in Table 8a.

TABLE 8a
Batches of cetrorelix	Pol.mic.,	0.22 μm	RRS,	Rat %
acetate lyophilizate	days	filter-	[%]	i.m.
(5 mg) . . .	without	able	after	after
Excipients	aggr.	[%]	1 h	6 h	168 h
only mannitol	0		—		about
(= control)					55
Solutol ®/mannitol	48	100
Cremophor ®/mannitol	46	101
Solutol ®/alanine	16	98	17	24
Solutol ®/alanine/	19	101	57	68	5.7
gluconic acid
Solutol ®/mannitol/	>45	100	84	88	3.8
gluconic acid
Cremophor ®/mannitol/	>45	101
gluconic acid
Solutol ®/tryptophan/	imposs.
mannitol
Solutol ®/tryptophan/	6				9.6
gluconic acid
Cyclodextrin molar	2	101	16	27	10
ratio 1:10/mannitol
Cyclodextrin molar	>45	102	68	74
ratio 1:10/mannitol/
gluconic acid
Cyclodextrin molar	17	100	68	76
ratio 1:30/mannitol
Cyclodextrin molar	5	101	39	52	6.3
ratio 1:10/alanine/
gluconic acid
Mannitol/citric acid	1	102	45	53
Solutol ®/mannitol/	>36	100	84	91	7.4
citric acid
Solutol ®/alanine/	1	99	47	54
citric acid
Solutol ®/glycine	>36	97	24	31
Solutol ®/urea	21	100	32	40
Solutol ®/glycine/	>36	99	82	89
gluconic acid
Solutol ®/urea/gluconic	>36	100
acid
Cremophor ®/alanine/	(36)
gluconic acid
Cremophor ®/urea/	(36)
gluconic acid
Pluronic ® F127/mannitol	1
5% Tween ® 80/mannitol	>16
Polyethylene glycol	1
4000/mannitol
Dextran/mannitol	1
Phenylmercury	2
acetate/mannitol

In the examples shown, it is evident that with a large number of the tested excipients from various groups of substances (surface-active substances, acids, amino acids, polymers, sugars, sugar alcohols, cyclodextrins, preservatives), stabilizing effects can be achieved in vitro (polarization microscopy, filterability, in-vitro release) and in vivo individually or with mixtures of these excipients. This reduced tendency to aggregate and thus improved in-vitro release of active compound also leads in the rat experiment to improved bioavailabilities of the peptide active compound and thus to reduced residual contents in the rat muscle.

Further in-vitro and in-vivo data of batches containing various cetrorelix salts without or with addition of stabilizing excipients are listed in Table 8b which follows:

TABLE 8b
		Pol.
		mic
Cetrorelix salts	Conc. of	days		Rat %
(reconstituted with	cetrorelix	with-	RRS, [%]	i.m.
water)	from lyo	out	after	after
Excipients	mg/ml	aggr.	1 h	6 h	168 h
Acetate	2.5	0	12	24.5	about
					55
Acetate	2.5	0	13	35.9	about
					55
Acetate	5	0	10	35
Acetate reconstituted	2.5	18	50	63.2	15.2
with gluconic acid
Acetate + Kollidon ®	2.5	84	15	43.4	20.2
12 PF
Acetate + Kollidon ®	2.5	98	22	50.6
17 PF
Acetate + benzalkonium	2.5		6.3	30.3
chloride
Acetate +	2.5		7.3	23.3
phospholipids
Acetate +	2.5		22.6	44.5	10
γ-cyclodextrin (1:10)
Acetate +	2.5		28	56.7
γ-cyclodextrin (1:30)
Acetate +	2.5		35.1	56.6
γ-cyclodextrin (1:50)
Acetate +	2.5	>168	34.5	60.2	3.6
γ-cyclodextrin (1:90)
Acetate +	5	140	19	47.8
γ-cyclodextrin (1:90)
Acetate +	7.5	20
γ-cyclodextrin (1:90)
Acetate +	10	4			45.2
γ-cyclodextrin (1:90)
Acetate reconstituted	15				49.1
with gluconic acid
Gluconate	2.5		18	45.3
Gluconate	2.5		11.3	46
Gluconate	2.5		77.5	83.6
reconstituted with
gluconic acid
Citrate	15		9	20.3
Lactate	bulk		20	55.2
Embonate	15		13	43

EXAMPLE 3

Cetrorelix formulations which are less prone/slower to aggregate (better filterability/polarization microscopy) and exhibit more rapid in-vitro release in Ringer's solution precipitate after 168 h in the rat muscle experiment owing to their lower residual content of cetrorelix. A higher bioavailability is expected of such formulations.

Some results of rat muscle experiments have already been listed in Tables 8a and 8b.

In the further rat muscle experiments shown in Table 9, in addition to the residual content in the muscle, the cetrorelix content in the plasma was additionally determined. With the aid of these data too, the stabilizing influence of the excipients tested is clear.

Moreover, it was possible by the replacement of the acetate salt by other salt forms of cetrorelix to achieve an improved bioavailability and, accompanying this, a reduced residual amount in the rat muscle experiment.

TABLE 9
		Cetrorelix	Cetrorelix	Cetrorelix
		concentra-	content in	content in
		tion of the	the muscle	the plasma,
Substance	Dose	inj. soln	(168 h), %	% of the
(cetrorelix)	(mg/kg)	(mg/ml)	of the dose	dose
Acetate +	1.5	2.5	5.7
Solutol ® +
alanine +
gluconic acid
Acetate +	1.5	2.5	9.6
Solutol ® +
tryptophan +
gluconic acid
Acetate + cyclo-	1.5	2.5	10.0	83.4
dextrin 1:10
Acetate + cyclo-	1.5	2.5	6.3	81.8
dextrin 1:10,
alanine,
gluconic acid
Acetate +	1.5	2.5	3.8
Solutol ® +
gluconic acid
Acetate +	1.5	2.5	7.4
Solutol ® +
citric acid
Acetate	1.5	3	55.1	92.2
Acetate in	1.5	3	22.3	74.2
Miglyol ®
Acetate +	1.5	3	76.9	39.8
benzalkonium
chloride
Acetate + 20%	1.5	3	3.6	106.2
cyclodextrin
Acetate + 20%	1.5	3	20.2	88.4
Kollidon ®
Acetate +	1.5	3	23.6	106.1
glucuronic acid
Acetate +	1.5	3	15.2	95.5
gluconic acid
Acetate + 20%	3.0	10	45.2	60.9
cyclodextrin
Acetate	3.0	15	56.5	28.7
Acetate in	3.0	15	24.2	57.2
Miglyol ®
Acetate + 0.025%	3.0	15	10.5	21.4
benzalkon.
Acetate +	3.0	15	78.1	43.8
glucuronic acid
Acetate +	3.0	15	49.1	45.5
gluconic acid
Gluconate	1.5	15	37.9	46.9
Gluconate in	1.5	3	24.6	58.0
mannitol
Gluconate in	1.5	3	25.4	75.2
mannitol
Gluconate in	1.5	3	28.8	46.3
Miglyol ®
Gluconate in	1.5	3	13.2	120.0
gluconic acid
Gluconate in	3.0	15	29.2
gluconic acid
Gluconate in	3.0	15	43.5	74.2
gluconic acid
Glucuronate	1.5	3	16.5	78.6
Glucuronate	3.0	15	18.8
Lactate	3.0	15	33.2	72.1
Lactate	1.5	3	30.7	67.1
Citrate lyo/a	1.5	3	22.8	36.6
Citrate in	1.5	3	14.8	53.1
Miglyol ®
Base	1.5	3	27.2	122.2
Base in Miglyol ®	1.5	3	38.9	55.9
Benzoate in
mannitol	1.5	3	34.2	32.7
Benzoate in	1.5	3	33.1	21.1
Miglyol ®
Phosphate	1.5	3	32.9	22.6

Claims

1. A pharmaceutical composition for parenteral administration, comprising: (a) a pharmaceutically effective amount of the peptidic LHRH antagonist salt cetrorelix acetate, in a concentration of 2.5 mg/ml total solution;(b) a pharmaceutically acceptable acid and % in total solution thereof, selected from the group consisting of gluconic acid of 0.00710%, 0.071, or 0.71%, or glucaric acid or galacturonic acid of 2.5%, wherein the pharmaceutically acceptable acid is present as free acid and is in an amount capable of imparting a pH of 2.5, 2.6, 3.1, 3.7, or 4.5 to the composition and suppressing aggregation of cetrorelix acetate; and(c) a carrier, wherein the carrier is water or an aqueous solvent mixture.

2. The pharmaceutical composition of claim 1, further comprising an excipient.

3. The pharmaceutical composition of claim 2, wherein the excipient comprises gluconic acid, glucuronic acid, galacturonic acid, glucaric acid, citric acid, ascorbic acid, or an amino acid.

4. The pharmaceutical composition of claim 2, wherein the excipient comprises polyethylene glycol 12(hydroxy)stearate (Solutol®), polyoxyethylene ricinoleate (Cremophor®), polysorbates, poloxamers, phospholipids, lecithins, or a preservative.

5. The pharmaceutical composition of claim 2, wherein the excipient comprises albumins, polyethylene glycols, cellulose derivatives, starch derivatives or polyvinylpyrrolidone.

6. The pharmaceutical composition of claim 2, wherein the excipient comprises cyclodextrins or its derivatives, or sugar alcohols.

7. The pharmaceutical composition of claim 2, wherein the excipient comprises urea or other chaotropic substances.

8. The pharmaceutical composition of claim 1, wherein the release of cetrorelix acetate is delayed by the use of a polymer.

9. The pharmaceutical composition of claim 8, wherein the Polymer is a homo- or copolymer of lactic or glycolic acid.

10. The pharmaceutical composition of claim 4, wherein the preservative is benzalkonium chloride or phenylmercury acetate.

11. The pharmaceutical composition of claim 6, wherein the sugar alcohol is mannitol.

12. The pharmaceutical composition of claim 1, wherein the pharmaceutical composition for parenteral administration is an injection preparation.

13. The pharmaceutical composition of claim 12, wherein the injection preparation is for subcutaneous injection.

14. The pharmaceutical composition of claim 2, wherein the excipient is independently selected from mannitol, polyethylene glycol 12-(hydroxyl)stearate, polyoxyethylene ricinoleate, glycine, citric acid and cyclodextrin.

15. The pharmaceutical composition of claim 1 manufactured by reconstitution of a lyophilisate of the cetrorelix acetate, wherein the reconstitution medium is water containing a pharmaceutically acceptable acid independently selected from gluconic acid or galacturonic acid.

16. The pharmaceutical composition of claim 1 manufactured by reconstitution of a lyophilisate of cetrorelix acetate, wherein the reconstitution medium is water containing a pharmaceutically acceptable acid independently selected from gluconic acid, glucaric acid and galacturonic acid.

17. The pharmaceutical composition of claim 1 manufactured by reconstitution of a lyophilisate consisting of the Cetrorelix salt and an excipient independently selected from mannitol, polyethylene glycol 12- (hydroxyl)stearate, polyoxyethylene ricinoleate, glycine, citric acid and cyclodextrin, wherein the reconstitution medium is water containing a pharmaceutically acceptable acid independently selected from gluconic acid, glucaric acid and galacturonic acid.