FORM 2
THE PATENTS ACT 1970
(39 of 1970)
AND
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rulel3)
1. TITLE OF THE INVENTION:
"LORAZEPAM LYOPHILIZED INJECTION"
2. APPLICANT:
(a) NAME: NEON LABORATORIES LTD.
(b) NATIONALITY: Indian Company incorporated under the
Companies Act, 1956
(c) ADDRESS: 140, Damji Shamji Industrial Complex, Mahakali Caves
Road, Andheri (East), Mumbai - 400093, Maharashtra, India.
3.PREAMBLE TO THE DESCRIPTION:
The following specification describes the nature of this invention and the manner
in which it is to be performed:

TECHNICAL FILED:
The present invention relates to a highly stabilized less viscous, hence effective pharmaceutical composition comprising Lorazepam lyophilized injection and process for the preparation thereof.
BACKGROUND AND PRIOR ART:
Lorazepam is a short to intermediate-acting antipsychotic drug of the class 3-hydroxy benzodiazepines; first introduced in around 1963 in US3296249 which discloses method of preparation of Lorazepam API and oral compositions in the form of tablet, capsule and suspensions.
Lorazepam drug has all six intrinsic benzodiazepine effects: anxiolytic, amnesic, sedative/hypnotic, anticonvulsant, antiemetic and muscle relaxant. It is used for the short-term treatment of anxiety, insomnia, acute seizures including status epilepticus and sedation of hospitalized patients, as well as sedation of aggressive patients. It exerts its therapeutic effects by interaction at the benzodiazepine binding sites located on GABAA receptors central nervous system.
Among benzodiazepines, lorazepam has a relatively high addictive potential. Lorazepam also has abuse potential; the main types of misuses are for recreational purposes or continued use against medical advice. Its sedative-hypnotic and anterograde amnesia properties are sometimes used for criminal purposes.
Due to tolerance and dependence, lorazepam is recommended for short-term use, up to two to four weeks only. Adverse effects, including anterograde amnesia, depression and paradoxical effects such as excitement or worsening of seizures may occur. Lorazepam impairs body balance and standing steadiness and is associated with falls and hip fractures in the elderly.
The oral, intranasal and injectable compositions of Lorazepam were introduced thereafter (WO2009027697, US2006147386, CN101194908). WO2004004783 discloses oral liquid formulations of benzodiazepines.

Lorazepam have been long-used for oral, intramuscular and/or intravenous administration. Lorazepam is currently marketed in an injectable and tablet formulations. Injectable formulations available in the market as non-aqueous or semi-aqueous solution having storage condition as cool place and have to be transported in refrigerated condition. These marketed formulations are quite un-stable at room temperature and even rate of degradation is higher at cool place. Non-aqueous injections of Lorazepam are highly viscous and thus very much painful while injecting.
Lyophilization or cryodesiccation is a dehydration process generally used to minimize the changes in the properties of the substances while improving its stability at or near room temperature. Lyophilization typically includes freezing the material at low temperature and vacuum and decreasing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase.
Lorazepam was generally administered in dosage forms like tablets, capsules and injection. As stated earlier, Lorazepam injection in conventional form had inherent problems of lack of stability at room temperature, viscousness, associated pains and discomfort in patient.
There is no report of any prior attempt of easy and economical processes for preparation of highly stable Lorazepam lyophilized injection.
The present invention overcomes the problems in the prior arts and provides a highly stable, less viscous on reconstitution and hence, therapeutically effective Lorazepam lyophilized injectable composition with optimum bioavailability.
SUMMARY OF THE INVENTION:
Stabilized injectable composition of Lorazepam in lyophilized form has been prepared and tested for stability, which has yielded highly stable injectable preparation.
Stability study indicated that the pharmaceutical acceptability standard has been achieved in the compositions of the present invention using terfiary butyl alcohol as a solvent and mannitol as a cryoprotectant.

DETAILED DESCRIPTION:
The details of the invention are described with certain optional and preferred embodiments so that various aspects of the invention may be fully understood.
The present invention overcomes the problems in the prior arts and provides a highly stable, less viscous on reconstitution and hence, therapeutically effective Lorazepam lyophilized injectable composition with optimum bioavailability.
The present invention relates to an economic, stable and therapeutically effective lyophilized injectable composition comprising Lorazepam, tertiary butyl alcohol, mannitol with water for injection
The present invention furtherprovides a process for preparation of lyophilized injection of Lorazepam includes the following steps;
1. Adding tertiary butyl alcohol in a part of water for injection;
2. Adding and dissolving Mannitol to product of step 1;
3. Adding Lorazepam to product of step 2 after complete solubilisation of Mannitol;
4. Stirring the mixture to get a clear solution;
5. Making required volume with water for injection and aseptically filtering with 0.2Μ filter;
6. Filling in amber vial, partially stoppering with gray bromo-butyl slotted rubber stoppers;
7. Lyophilising the product of step 6.
Preferred embodiment of the composition which resulted in the pharmaceutically acceptable and effective composition is provided.
Table 1

Sr. No. Ingredients Quantity /vial
1. Lorazepam 4.0 mg
2. Tertiary Butyl Alcohol 0.6 ml
3. Mannitol 10 mg
4. Water for Injection Upto 1 ml

pH should be in between 5.5 to 6.5. In the preferred embodiment of the invention, formulation is with 60 % v/v tertiary butyl alcohol.
Extensive stability studies have been conducted at long term, accelerated as well as stress temperature and humidity storage conditions, 2°-8°C, Below 25°C and 30° C/ 75% RH on the formulations prepared with 60% TBA packed in 13 mm; 3 ml amber coloured USP type I vials protected from light & moisture.
Stored samples of the formulations were periodically evaluated for stability assays by HPLC analytical method (Assay by HPLC in range of 90 to 100%) and also for Particulate matter, impurity profiling, water content and Bacterial Endotoxins Testing (BET).
Formulations exhibited no significant change in its standard parameters during stability studies and thus exhibited pharmaceutically acceptable stability.
Thus, the present invention advantageously provides economic and highly stable lyophilised injectable compositions of lorazepam.
As described earlier the present invention discloses a stable and therapeutically effective lyophilized injectable composition comprising Lorazepam, tertiary butyl alcohol, mannitol with water for injection.
While, the reconstitution solvent includes 48% v/v propylene glycol, 12% polyethylene glycol-400 and 40% v/v water for injection.
Preferably, the above-described lyophilized preparation for injection comprises approximately 4 mg/vial of Lorazepam, the solvent Tertiary Butyl Alcohol in 0.6ml /vial and cryoprotectant; Mannitol in an amount of 10 mg/vial.
Preferably, the reconstitution solvent includes 48% v/v propylene glycol, 12% polyethylene glycol-400 and 40% v/v water for injection.

A process for preparation of lyophilized injection of the lorazepam includes the following steps;
1. Adding tertiary butyl alcohol in water for injection and dissolving Mannitol to the solution;
2. Adding Lorazepam to product of step 1 after complete solubilization of Mannitol;
3. Stirring the mixture to get a clear solution; Making required volume with water for injection and aseptical filtering with 0.2μ filter;
4. Filling in amber vial, partially stoppering with graybromo-butyl slotted rubber stoppers;
5. Lyophilising the product of step 6.

Table 2

Sr. No. Parameters STD Limit Withdrawal Period

Initial (08/07/12) 1M 2M (07/08/2012) 3M (07/09/2012) 6M (08/12/2012)

Below
25°C 30° C/ 75%RH Below 25°C 30° C/ 75% RH 2°-8°C Below
25°C 30° C/ 75%RH 2£>-8°C Below
25°C 30° C/ 75%RH
1. Description * * * * * * * * * * * *
2. pH (Reconstituted soln.) Between 5. 5 & 7. 0 6.78 6.724 6.654 6.703 6.702 6.258 6.226 6.320 6.36 6.37 6.38
3. Particulate matter Visual Inspection ** ** ** ** ** ** ** ** ** ** ** **
4. % Transmittance At 430 nm At 550 nm NLT 98.0% NLT 98.0% 99.276% 99.931% 99.245% 99.247% 98.257% 98.354% 98.33% 99.034% 98.11% 98.84% 98.265% 98.222% 98.962% 98.744% 98.912% 98.111% 98.29% 99.34% 98.41% 99.01% 98.73% 98.77%
5. Water NMT 5.0% 1.26% 1.39% 1.57% 4.49% 2.54% 3.57% 2.94% 2.34% 1.54% 1.38% 1.54%
6. Related Substance Total Imp. NMT4.0% Nil 0.098% 0.184% 0.925% 0.209% 0.965% 0.376% 0.666% 1.1803% 1.562% 2.196%
7. Bacterial Endotoxins NMT lOO EU/mg Complies Not required
8. Assay NLT 90.0% to NMT 110.0% 103.19% 101.57% 102.65% 98.78% 97.25% 99.13% 99.04% 94.02% 100.97% 100.56% 97.98%

* A white lyophilized mass. ** Reconstituted solution free from particulate matter visible to unaided eyes.
Remark: 1) The product found stable for 6 months even at stress condition of 30°C - 75%RH.
2) The storage condition of liquid Injectable composition is 2 to 8°C while the lyophilized product found stable for 6 months even at 30°C± 2°C 75%
± 5% RH
3) From the above stability data we may conclude that the lyophilized composition can be stored at room temperature for longer period.

Table 3

Sr. Parameters STD Limit Withdrawal Period
No.

Initial
(08/07/12) 1M (07/08/2012) 2M (06/09/2012) 3M (29/09/2012) 6M (31/12/2012)



2°-8°C Below 25°C 30° C/ 75% RH 2°-8°C Below
25°C 30° a
75%RH 2°-8°C Below 25°C 30° a
75%RH 2°-8°C Below 25°C 30° O 75%RH
I. Description * * * * * * * * * * * * * *
2. pH (Reconstituted soln.) Between 5. 5 & 7. 0 6.84 6.27 6.27 6.23 6.34 6.24 6.25 6.276 6.317 6.24 6.35 6.29 6.34
3. Particulate matter Visual Inspection ** ** ** ** ** ** ** ** ** ** ** ** ** **
4. % Transmittance At 430 nm At 550 nm NLT 98.0%
NLT 98.0% 98.485% 99.095% 98.830% 99.513% 98.476% 99.156% 98.436% 99.152% 98.717% 99.676% 98.424%
99.763% 98.313% 99.417% 98.703% 98.488% 98.739% 99.488% 98.721% 99.481% 99.92% 99.88% 99.72%
99.71% 99.59% 99.62%
5. Water N.M.T. 5.0% 2.54% 2.65% 2.63% 3.22% 2.45% 2. 88% 2. 38% 2.84% 2.64% 2.47% 2.47% 2.58% 2.64%
6. Related Substance Total mi p. NMT 4.0 % Nil 0.649% 0.874% 0. 39% 1.163% 0. 565% 0. 956% 0. 985% 0. 802% 1.569% 1.167% 1.69% 2.66%
7. Bacterial Endotoxins NMTlOOEU/mg Complies Not required
8. Assay NLT 90.0% to NMT 110.0% 101.37% 99.03% 108.93% 103.25% 98.70% 97.83% 98.72% 94.66% 96.74% 94.70% 97.72% 95.26% 94.77%

* A white lyophilized mass ** Reconstituted solution free from particulate matter visible to unaided eyes.
Remark: 1) The product found stable for 6 months even at stress condition of 30°C - 75%RH.
2) The storage condition of liquid Injectable composition is 2 to 8°C while the lyophilized product found stable for 6 months even at 30°C± 2°C 75% ± 5% RH
3) From the above stability data we may conclude that the lyophilized composition can be stored at room temperature for longer period.

WE CLAIM,
1. A pharmaceutical composition in an injectable formulation characterized in that
the said composition comprises Lorazepam in an amount of 0.5 - 4mg, tertiary butyl alcohol in an amount of 0.3-1 ml, mannitol as a cryoprotectant in an amount of 5 to 25 mg and water for injection wherein the said composition in lyophilised formis thereby made to have pharmaceutically acceptable stability at room temperature and optimum bioavailability.
2. A process for preparing the composition as in claim 1, comprising
i. Adding Tertiary butyl alcohol in a part of water for injection;
ii. Adding and dissolving Mannitol;
iii. Adding Lorazepam to product of step 2 after complete solubilization of
Mannitol; iv. Stirring the mixture to get a clear solution; v. Making required volume with water for injection aseptical filtering with
0.2LX filter; vi. Filling in amber vial, partially stoppering with graybromo-butyl slotted
rubber stoppers; vii.Lyophilising the product of step vi.
3. A pharmaceutical composition as in claiml, wherein Lorazepam is in the amount
of 0.5 to 4mg.
4. A pharmaceutical composition as in claiml, wherein tertiary butyl alcohol is in
the amount of 0.3 to 0.6 ml.
5. A pharmaceutical composition as in claiml, wherein tertiary butyl alcohol is in
the amount of 0.6 ml.

6. A pharmaceutical composition as in claiml, wherein Mannitol is in the amount of
5 mg to 25 mg.
7. A pharmaceutical composition as in claiml, wherein Mannitol is in the amount of
10 mg.