STABLE LIQUID FORMULATIONS OF MELPHALAN

Abstract

The present invention relates to stable, liquid parenteral formulations of Melphalan or pharmaceutically acceptable salts thereof. Further this invention also describes process of preparing such formulations.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a U.S. National Phase filing under 35 U.S.C. .sctn. 371 of International Application PCT/IB2016/053881, filed Jun. 29, 2016, and published as WO 2017/002030 A1 on Jan. 5, 2017. PCT/IB2016/053881 claims priority from Indian application number 3328/CHE/2015, filed Jun. 30, 2015. The entire contents of each of these applications are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] Melphalan, also known as L-phenylalanine mustard, L-PAM, or L-sarcolysin is a phenylalanine derivative of nitrogen mustard. Melphalan is a bifunctional alkylating agent that is active against selected human neoplastic diseases. The molecular formula is C.sub.13H.sub.18C.sub.12N.sub.2O.sub.2 and the molecular weight is 305.20. The structural formula is:

##STR00001##

[0003] U.S. Pat. No. 4,997,651 to Stephen et al., discloses two-component pharmaceutical formulation of Melphalan comprising freeze-dried Melphalan hydrochloride and a solvent-diluent comprising a citrate, propylene glycol and ethanol.

[0004] U.S patent application No. 2013/0131174 to Castillo et al., discloses a solid lyophilized composition of Melphalan hydrochloride having a pH between 4 and 6.

[0005] U.S patent application Nos. 2010/0311838, 2014/0213650 and 2014/0221488 disclose parenteral compositions comprising Melphalan and a cyclodextrin derivative.

[0006] RU2060031 discloses parenteral lyophilized formulation comprising a Melphalan, polyvinylpyrrolidone, ascorbic acid, glutamic acid, hydrochloric acid and D-mannitol.

[0007] The commercial formulation of injectable Alkeran.RTM. consists of two components comprising of Melphalan hydrochloride and polyvinylpyrrolidone lyophilized and a diluent comprising a mixture of sodium citrate, water for injection, propylene glycol and ethanol.

[0008] The Alkeran.RTM. to be infused must be diluted to not more than 0.45 mg/ml in normal saline and infused over 15 minutes.

[0009] The reconstitution of the lyophilized product is clinically inconvenient and the lyophilization process is time consuming and often incurs significant expense. Hence, there is a strong need to develop alternate formulations of Melphalan.

[0010] The inventors have developed ready to use liquid formulation of Melphalan which overcomes the disadvantages of the formulations reported in prior art.

SUMMARY OF THE INVENTION

[0011] One object of the invention provides ready to use liquid parenteral formulation of Melphalan.

[0012] Another aspect of the present invention is to provide ready to use liquid parenteral formulation comprising Melphalan, one or more solvents, anti-oxidants and other pharmaceutically acceptable adjuvants thereof.

[0013] Yet another aspect of the present invention provides method for preparing ready to use liquid parenteral formulation of Melphalan comprising Melphalan Hydrochloride, one or more solvents, anti-oxidants and other pharmaceutically acceptable adjuvants thereof.

DETAILED DESCRIPTION OF THE INVENTION

[0014] In the context of this invention "Melphalan" refers to the pharmaceutically acceptable salts, solvates, hydrates and anhydrous forms thereof, preferably Melphalan Hydrochloride.

[0015] As used herein, "ready to use" Melphalan formulations refers to formulations that contain Melphalan in dissolved or solubilized form and are intended to be used as such or upon further dilution in intravenous diluents.

[0016] In one embodiment, ready to use liquid parenteral formulations of Melphalan comprise

[0017] i. Melphalan,

[0018] ii. one or more solvents,

[0019] iii. anti-oxidants,

optionally other pharmaceutically acceptable adjuvants thereof.

[0020] In yet another embodiment, ready to use liquid parenteral formulations of Melphalan comprise

[0021] i. Melphalan Hydrochloride,

[0022] ii. one or more solvents selected from the group comprising of dimethylacetamide, polyethylene glycol, ethanol, propylene glycol and glycerine,

[0023] iii. anti-oxidants selected from monothioglycerol, L-cysteine, ascorbic acid and optionally other pharmaceutically acceptable adjuvants thereof.

[0024] The composition according to the present invention is intended to be stored at a temperature of 2-8.degree. C.

[0025] Suitable solvents include, but are not limited to dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), N-methylpyrrolidone, dimethylisosorbide, ethanol, propylene glycol, glycerine, polyethylene alcohol, propylene glycol esters, polyethylene glycols and the like. Preferred solvents are dimethylacetamide (DMA), ethanol, polyethylene glycols (PEG), glycerine and propylene glycol.

[0026] The pharmaceutical compositions of the present invention also contain one or more anti-oxidants selected from the group, but not limited to butylated hydroxyanisole (BHA), butylated hydroxyl toluene (BHT), citric acid, lactic acid, benzoic acid, tocopherol (Vitamin E), ethylenediaminetetraacetic acid, sodium metabisulfite, sodium bisulfite, monothioglycerol, ascorbic acid and their esters, L-cysteine, parabens, benzyl alcohol, propyl gallate, thioglycolic acid, tartaric acid, phosphoric acid, gluconic acid, thiodipropionic acid, acetonic dicarboxylic acid, amino acids such as histidine, cysteine, tryptophan, tyrosine; chelating agents and the like. Most preferred anti-oxidant is monothioglycerol.

[0027] The formulation of the present invention may additionally contain buffers, pH adjusting agents, stabilizers such as, but not limited to citrate buffer, glutamate, dicarboxylic acid, lecithin, di(hydroxyethyl)glycine, sorbitol, bicarbonate, tartrate, benzoate, lactate, gluconate, glycine, TRIS buffer, acetate buffer, boric acid buffer, phosphate buffer, amino acids, meglumine and the like.

[0028] Solubility studies were carried out with various solvents at 25.degree. C. temperature, to check the solubility of Melphalan hydrochloride. The data is summarized in table 1:

TABLE-US-00001 TABLE 1 Solubility studies in various solvents Quantity of solvents Qty of Melphalan PEG- Propylene Hydrochloride DMA 400 Glycol Ethanol Result 100 mg 1.1 mL -- -- -- Clear 100 mg 0.5 mL -- -- 0.5 mL Clear 100 mg -- -- 1 mL -- Not Clear 100 mg -- -- -- 1 mL Hazy solution 100 mg 0.3 mL -- 0.05 mL 0.65 mL Clear 100 mg -- 1.0 mL 0 mL -- Clear after vigorous mixing 100 mg -- 0.9 mL 0.1 mL -- Clear 100 mg -- 0.7 mL 0.3 mL -- Clear 100 mg -- 0.5 mL 0.5 mL -- Clear 100 mg -- 0.2 mL 0.8 mL -- Clear 100 mg -- 0.1 mL 0.9 mL -- Clear

[0029] In one of the preferred embodiment, ready to use liquid parenteral formulations of Melphalan comprise:

TABLE-US-00002 i. Melphalan Hydrochloride 1 to 30% ii. dimethylacetamide or polyethylene glycol 20 to 95% iii. ethanol 0 to 50% iv. propylene glycol. 5 to 50% v. monothioglycerol 0.05 to 5%

by weight of the composition.

[0030] The invention further relates to a process of preparing liquid formulations of Melphalan. The process comprises:

[0031] i. Addition of Melphalan to the manufacturing vessel containing solvent and stirred till a clear solution is obtained.

[0032] ii. Addition of remaining solvents to the above solution and stirred.

[0033] iii. Addition of anti-oxidant to the solution and stirred till a homogenous solution is obtained.

[0034] iv. Filtering and filling the solution in to suitable containers or vials.

[0035] Melphalan formulation prepared according to the invention was tested for stability at various stability conditions such as 2-8.degree. C. and 25.degree. C./60% RH for a period of 6 months. Stability data is summarized in table 2.

TABLE-US-00003 TABLE 2 Stability data for the product obtained from Example 5 Condition 2-8.degree. C. 25.degree. C./60% RH Time point Initial 1 M 3 M 6 M 1 M 3 M 6 M Assay By HPLC (%) 99.2 97.8 97.7 96.8 97.2 94.0 90.1 Total Impurities 0.17 0.24 0.32 0.75 0.89 2.26 4.33 (% w/w)

[0036] Surprisingly no significant increase in total impurities was observed even at 25.degree. C./65% RH. The inventors have found that liquid pharmaceutical formulation of Melphalan comprising of one or more solvents selected form DMA, Ethanol, PEG and propylene glycol in the presence of an anti-oxidant yields a stable liquid formulation of Melphalan overcoming the disadvantages associated with prior art.

[0037] Comparative dilution studies were performed to check the stability of the diluted formulations. Melphalan formulation prepared according to the invention was diluted with 0.9% NaCl to get concentration of 0.45 mg/mL. Alkeran.RTM. vial (Batch No: P283) was considered as reference for comparative dilution study. Stability of the diluted product was studied at 0 minutes, 30 mins and 60 min. The stability data of the invention formulation and reference product is summarized in table 3.

TABLE-US-00004 TABLE 3 Comparative dilution study of the invention formulation with reference product Dilution study with 0.9% NaCl Formulation Reference product Invention formulation after reconstitution with after dilution with diluent, followed by 0.9% NaCl dilution with 0.9% NaCl Time point Initial 30 min 60 min Initial 30 min 60 min Assay (%) 97.3 97.6 95.2 95.6 91.1 88.2 pH of Solution 3.51 3.48 3.48 5.83 6.06 6.35 Osmolality 352 348 354 1120 1119 1122 (mOsm/kg) Related Substances Impurities % (w/w) Impurity D 1.23 3.31 5.35 1.11 3.67 5.73 Impurity G 0.14 0.15 0.17 0.49 0.52 0.51 Total 1.6 3.8 5.8 1.94 5.08 7.65 Impurities

[0038] Surprisingly Melphalan formulation prepared according to the invention showed better stability profile compared to the reference product.

[0039] The following examples further describe certain specific aspects and embodiments of the present invention and demonstrate the practice and advantages thereof.

Example 1

TABLE-US-00005

[0040] Qty/vial Ingredients (mg) Melphalan Hydrochloride 20-200 N,N,Dimethyl acetamide 350-490 Ethanol 200-280 Propylene glycol 180-270 Monothioglycerol 3-8

Manufacturing Process

[0041] Melphalan Hydrochloride was added to the manufacturing vessel containing N, N, Dimethyl acetamide and ethanol and stirred to get a clear solution. Propylene glycol was added, followed by the addition of monothioglycerol and stirred to get homogenous solution. The obtained solution was filtered and filled in vials followed by capping and sealing.

[0042] Melphalan formulation prepared according to the invention was tested for stability at various stability conditions such as 2-8.degree. C. and 25.degree. C./60% RH for a period of 6 months. Stability data is summarized in table 4.

TABLE-US-00006 TABLE 4 Stability data for the product obtained from Example 1 Condition 2-8.degree. C. 25.degree. C. Time point Initial 1 M 3 M 6 M 1 M 3 M 6 M Assay By 100.3 100.3 103.3 98.3 99.5 101.1 94.4 HPLC (%) Total 0.19 0.16 0.20 0.63 0.30 1.60 4.37 impurities *RRT: Relative Retention Time

Example 2

TABLE-US-00007

[0043] Qty/vial Qty/vial Qty/vial Ingredients (mg) (mg) (mg) Melphalan 20-200 20-200 20-200 Hydrochloride N, N, Dimethyl 380 380 380 acetamide Ethanol 240 320 280 Propylene glycol 310 210 260 Monothioglycerol 2.53 5.05 5.05

Manufacturing Process

[0044] Melphalan Hydrochloride was added to the manufacturing vessel containing N,N,dimethyl acetamide and ethanol and stirred to get a clear solution. Propylene glycol was added, followed by the addition of monothioglycerol and stirred to get homogenous solution. The obtained solution was filtered and filled in vials followed by capping and sealing.

Example 3

TABLE-US-00008

[0045] Qty/vial Ingredients (mg) Melphalan Hydrochloride 20-200 Polyethylene glycol 570 Ethanol 240 Propylene glycol 210 Monothioglycerol 5.05

Manufacturing Process

[0046] Melphalan Hydrochloride was added to the manufacturing vessel containing polyethylene glycol and ethanol and stirred to get a clear solution. Propylene glycol was added, followed by the addition of monothioglycerol and stirred to get homogenous solution. The obtained solution was filtered and filled in vials followed by capping and sealing.

Example 4

TABLE-US-00009

[0047] Quantity/vial Ingredients (mg) Melphalan Hydrochloride 20-200 Polyethylene glycol-400 490-620 Propylene glycol 320-390 Monothioglycerol 5.05

Manufacturing Process

[0048] Melphalan Hydrochloride was added to the manufacturing vessel containing polyethylene glycol. Propylene glycol was added, followed by the addition of monothioglycerol and stirred to get homogenous solution. The obtained solution was filtered and filled in vials followed by capping and sealing.

Example 5

TABLE-US-00010

[0049] Quantity/vial Ingredients (mg) Melphalan Hydrochloride 20-200 Polyethylene glycol-400 590-950 Propylene glycol 120-420 Monothioglycerol 5-8

Manufacturing Process

[0050] Melphalan Hydrochloride was added to the manufacturing vessel containing polyethylene glycol. Propylene glycol was added, followed by the addition of monothioglycerol and stirred to get homogenous solution. The obtained solution was filtered and filled in vials followed by capping and sealing.

Claims

1. (canceled)

2: The formulation of claim 3, wherein the pH of the formulation is between 2 to 5.

3: A stable, liquid parenteral formulation consisting essentially of: (i) Melphalan (ii) one or more solvents and (iii) one or more anti-oxidants.

4: A stable, liquid parenteral formulation consisting essentially of: (i) Melphalan hydrochloride (ii) one or more solvents selected from dimethyl acetamide, polyethylene glycol, ethanol, propylene glycol and glycerine. (iii) anti-oxidants selected from monothioglycerol, L-cysteine and chelating agents.

5. (canceled)

6: The stable, liquid parenteral formulation of claim 4 consisting of: TABLE-US-00011 (i) Melphalan hydrochloride 1 to 30% (ii) dimethylacetamide 20 to 85% (iii) ethanol 0 to 50% (iv) propylene glycol 5 to 50% (v) at least one of monothioglycerol, chelating agent, 0.05 to 5% and both in combination by weight of the composi- tion.

7: The stable, liquid parenteral formulation of claim 4 consisting of: TABLE-US-00012 (i) Melphalan hydrochloride 1 to 30% (ii) polyethylene glycol 20 to 85% (iii) ethanol 0 to 50% (iv) propylene glycol 5 to 50% (v) at least one of monothioglycerol, chelating agent, 0.05 to 5% and both in combination by weight of the composi- tion.

8: A stable, liquid parenteral formulation of Melphalan consisting essentially of: TABLE-US-00013 (i) Melphalan hydrochloride 1 to 30% (ii) polyethylene glycol 20 to 85% (iii) propylene glycol 5 to 50% (iv) monothioglycerol 0.05 to 5% (v) chelating agent by weight of the composition. 0.01 to 5%