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:
"A STABLE LYOPHILIZED INJECTION OF ATRACURIUM BESYLATE"
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 FIELD:
The present invention provides the highly stabilized composition of Lyophilised Injectable dosage form of Atracurium besylate.
BACKGROUND AND PRIOR ART:
' Atracurium besylate is a neuromuscular-blocking drug or skeletal muscle relaxant in the category of non-depolarizing neuromuscular-blocking drugs, used adjunctively in anesthesia to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation. Atracurium is classified as an intermediate-duration non-depolarizing neuromuscular-blocking agent.
Atracurium Besylate as solid (Lyophilised) powder is much more stable than in liquid injection form which indicates much more stability of API in solid form rather than liquid form. Currently available (Marketed) formulation of Atracurium Besylate is a sterile solution of Atracurium Besylate in water for injection which shows high degradation and there by development of impurities on storage. Majority of impurities specified for Atracurium Besylate are the isomeric form of Atracurium Besylate. Such isomeric impurities are majorly generated when the API is in solution form.
The administration of Atracurium besylate through the vascular pathway, such as intravenous injection has an advantage of an immediate response and the response may also be easily controlled.
Atracurium injection involves stability problems mainly caused by chemical and physical factors such as light, heat and pH-sensitivity. The stability of the solution is dependant on physical and chemical factors, thus limiting the shelf life of the solution, results in degradation products.
Also, the atracurium besylate injection need to be stored at temperature between 2°C to 8°C, and at a pH between 3 to 4,however, with extended storage time, the stability of atracurium besylate is decreased and related impurities increased thus affect the efficacy of the drug.

In the above context, there are few prior arts which have tried to overcome the problems involved in the injectable atracurium besylate. One such solution is disclosed in CN10053173.
CN10053173 discloses freeze dried composition of atracurium. The composition adopts atracurium or its pharmaceutically acceptable salt or optical isomer as active ingredient, which comprises atracurium, sugar and an organic acid. The invention also discloses a method for preparing the composition.
GB2445746 discloses carbonated water may be used as a solvent for freeze drying. A crude organic compound may be purified by dissolving it in carbonated water to form a solution and subsequently freeze drying the solution to yield the compound with a reduced level of residual solvent. The carbonated water preferably has a pH less than 6 prior to dissolution and is optionally further carbonated during or after dissolution to restore a pH of less than 8. One such organic compound is atracurium.
In view of the above, there is still a need in the art to provide atracurium besylate in stable lyophilized injectable form with low impurity profile.
Therefore, the object of the invention is to provide a stable lyophilized injectable atracurium besylate with low impurity profile and thus to have long therapeutic stability.
SUMMARY OF THE INVENTION:
In accordance with the above, the present invention provides a freeze dried composition of atracurium besylate comprising atracurium besylate; an organic acid to adjust the pH, a co-solvent along with water as a principle solvent and to the process for preparation thereof.
In an aspect, the present composition is a stable lyophilized injectable with low impurity profile by minimizing the degradation.
DETAILED DESCRIPTION OF THE INVENTION:
In accordance with the objective, the invention provides stable lyophilized injectable atracurium besylate with low impurity profile by minimizing the degradation.

The rational of current invention is to minimize the degradation of atracurium besylate throughout its shelf life and to provide the resultant dosage with maximum stability and with low impurity profile. Therefore, the invention provides a Iyophilized product that allows the API in anhydrous form and thereby reduces the degradation rate and provides maximum stability with reduction in impurities generation.
The purpose of providing the freeze dried atracurium besylate is to reduce the generation of impurities.
Accordingly, the instant invention provides a freeze dried composition of atracurium besylate comprising atracurium besylate; an organic acid to adjust the pH, a co-solvent along with water as a principle solvent.
In a preferred embodiment, the instant freeze dried composition comprises atracurium besylate; Benzene Sulphonic Acid to adjust the pH and tertiary butanol as co-solvent and water as a principle solvent.
In another preferred embodiment, the invention provides a process for preparation of freeze dried composition which comprises:
a) Dissolving atracurium besylate in a part of water for injection, followed by addition and mixing of co-solvent;
b) Adj listing the pH of the solution upto 4±0.1.
c) Making up the required volume with water for injection followed by aseptically filtering with 0.2μ filter;
d) Filling the solution in amber vial, partially stoppered with gray bromo-butyl slotted rubber stoppers and Lyophilised; and
e) Optimizing the Lyo recipe without pressure rise test to obtain desired moisture content.
In yet another preferred embodiment, the invention provides stability studies of the instant composition, wherein, the Assay of the drug in the range of N.L.T. 90% -N.M.T. 110% with total impurities - N.M.T. 20.0% and Laudanosine impurity N.M.T 3.0% at a temperature of 2°C - 8°C.

The following examples, which include preferred embodiments, will serve to illustrate the practice of this invention, it being understood that the particulars shown are by way of example and for purpose of illustrative discussion of preferred embodiments of the invention.
Example: 1

Sr.
No. Ingredients Quantity / vial OA Batch Formula (75 Vials) Use
1. Atracurium besylate 25 mg — 1.875 x Fgm Active
2. Benzene Sulphonic Acid (0.2%) q.s q.s For pH adjustment
3. Tertiary Butyl alcohol 1.5 ml ~ 112.5ml. Co-solvent
4. Water for injections q.s 2 ml ~ q.s 150 ml Solvent
Procedure:
a) Dissolving atracurium besylate in a part of water for injection, followed by addition
and mixing of co-solvent;
b) Adjusting the pH of the solution 4±0.1
c) Making up the required volume with water for injection followed by aseptically
filtering with 0.2u filter;
d) Filling the solution in Amber vial, partially stoppered with gray bromo-butyl slotted
rubber stoppers and Lyophilised;
e) Optimizing the Lyo recipe without pressure rise test to obtain desired moisture
content.
In accordance with the preferred embodiment, the inventors have provided the stability report for the various batches manufactured. The detailed stability data of the same is given below:

Stability report: Table 1

Product Name: ATRACURIUM BESYLATE FOR INJECTION (Lyophilised) Pharmacopoeia: NP
Generic Name: ATRACURIUM BESYLATE FOR INJECTION Strength: 25 mg /vial Batch No.: 11121587
Primary packing: 5 ml Amber colour tubular USP Type I Vial.
Storage condition: Store between 2° and 8°C, Protected from light.

Sr.
No. Parameters STD Limit Withdrawal Period

Initial 1M 3M 6M 9M 12M

2°-8°C 2° - 8°C 2° - 8°C 2° - 8°C 2° - 8°C
1. Description A White
Lyophilised
mass. Complies Complies Complies Complies Complies Complies
2. pH(of Reconstituted) Between 3.0 to 4.0 3.56 3.43 3.48 3.45 3.31 3.39
3. Related
substance
(By HPLC)
A)Laudanosine NMT 3.0% 0.27% 0.24% 0.2650% 0.29% 0.28% 1.1452%
B) Total
Impurities. NMT20.0% 1.13% 1.76% 2.94% 5.346% 11.00% 17.0%
4. Assay (By HPLC) N.L.T. 90.0%
and N.M.T.
110.0% 99.28% 98.73% 98.35% 96.48% 94 .58% 93.4%
5. Water content NMT 5.0% 2.08% 2.15% — — — 4.24%

Example: 2
• As per initial stability studies of earlier optimized batches overages up to 10% were added to compensate atracurium besylate in actual stability batches.

Sr.
No. Ingredients Quantity / vial OA Batch Formula Use
1. Atracurium besylate 25 mg 10% 2.0625 x F gm Active
2. Benzene Sulphonic Acid (0.2%) q.s q.s For pH adjustmen
3. Tertiary Butyl alcohol 1.5 ml — 112.5ml. Co-solvent
4. Water for injections q.s 2 ml — q.s 150 ml Solvent
Stability report: Table 2

Product Name: ATRACURIUM BESYLATE FOR INJECTION (Lyophilised) Pharmacopoeia: NP
Generic Name: ATRACURIUM BESYLATE FOR INJECTION Strength: 25 mg / vial Batch No.: 11121585
Primary packing: 5 mi Amber colour tubular USP Type I Vial.
Storage condition: Store between 2° and 8°C, Protected from light.

Sr. No. Parameters STD Limit Withdrawal Period

Initial 1M 3M 6M 12M

2° - 8°C 2° - 8°C 2° - 8°C 2° - 8°C
1. Description A White
Lyophilised mass. Complies Complies Complies Complies Complies
2. pH
(of Reconstituted) Between 3.0 to
4.0 3.75 3.86 3.48 3.26 3.39
3. Related substance (By HPLC)
A) Laudanosine NMT 3.0% 0.77% 1.42% 2.088% 2.93% 2.44%
B) Total Impurities NMT 20.0% 2.025% 3.11% 3.47% 6.993% 7.39%

Assay (By HPLC) NX.T. 90.0% and N.M.T.110.0% 109.35% 107.20% 105.82% 102.02% 100.75%
4. Water NMT 5.0% 2.98% — --- 3.02% 4.69%
Stability report: Table 3

Product Name: ATRACURIUM BESYLATE FOR INJECTION Pharmacopoeia: NP
Generic Name: ATRACURIUM BESYLATE FOR INJECTION Strength: 25 mg/ Batch No.: vial 12061841
Primary packing: 5 ml Amber colour tubular USP Type I Vial.
Storage condition: Store between 2° and 8°C, Protected from light.

Sr. No. Parameters STD Limit Withdrawal Period

Initial 1M 2M 3M 8M 12 M

2° - 8°C 2° - 8°C 2° - 8°C 2° - 8°C 2° - 8°C
1. Description White to
off white
Lyophilised
mass. To Comply Complies Complies Complies Complies Complies
2. pH(of
Reconstituted) Between 3.0 to 4.0 3.60 3.00 3.71 3.03 3.12 3.10
3. Related substance (By HPLC)
A)Laudanosine B) Total NMT 3.0% 0.10%, 0.2% 0.517% 0. 53%, 1.20% 1.26%
Impurities NMT
20.0% 3.68% 3.20% 1.80% 6. 247% 11.90% 15.47%
4. Assay (By HPLC) N.L.T. 90.0%
and N.M.T.
110.0% 102. 54% 111.06% 109.25% 105.19% 102.42% 100.9%

Lyo recipe:
Lyophilization of said composition comprises following stages-
• Precooling with rapid cooling rate of ] .5 C-2 C per min.. to freeze product approx.to-20°C to -30°C
• Primary drying for 20 hrs by applying vacuum of 0.700mbar in temperature range
of-30°C to O°C.
• Secondary drying under reduced pressure up to 1O °C.

We claim,
1. A freeze dried composition of atracurium besylate comprising atracurium besylate; an acid to adjust the pH and a co-solvent along with water as a principle solvent.
2. The freeze dried composition according to claim 1, wherein, the acid is Benzene
Sulphonic Acid and the co-solvent is tertiary butanol.
3. A process for preparation of freeze dried composition which comprises:
a) Dissolving atracurium besylate in a part of water for injection, followed by addition and mixing of co-solvent;
b) Adjusting the pH of the solution upto 4±0.1
c) Making up the required volume with water for injection followed by aseptically filtering with 0.2μ filter;
d) Filling the solution in Amber vial, partially stoppered with gray bromo-butyl slotted rubber stoppers and Lyophilised; and
e) Optimizing the Lyo recipe without pressure rise test to obtain desired moisture content.
4. The process according to claim 3, wherein the co-solvent is Tertiary Butyl
alcohol.