## STP FOR BACLOFEN TABLETS

1.0) Description: Visual

2.0) Average Weight: Check weight of 20 tablets at randomly and calculate the average weight by formula :

wt of 20 tablets (gm) x 1000 / 20. found avg. wt in mg

3.0)   Uniformity of weight:

Weigh 20 tablets selected at random and calculate the average weight. Not more than two of the individual weights deviate from the average weight by more than the percentage shown in table.

Tablets were weighed individually and the percentage of deviation of its weight from the average weight was determined for each tablet. Formula for calculate the percentage of deviation = (experimental weight – theoretical weight)    x 100%

Theoretical weight

 Average weight of tablets Percentage deviation More than 80mg but Less than 250mg 7.5% 250mg or More 5%

4.0)      Identification Test:

1. Determine by thin-layer chromatography, coating the plate with silica gel G.

Solvent mixture: 4 volumes of ethanol and 1 volume of glacial acetic acid.

Mobile phase: A mixture of 80 volumes of butan-1-ol, 20 volumes of G.A.A. and 20 volumes of water.

Test solution: Shake a quantity of the powdered tablets containing 20mg of Baclofen with 20ml of the solvent mixture for 30 minutes and filter.

Reference solution: A 0.1 per cent w/v solution of baclofen reference standard in the solvent mixture.

Apply to the plate 5µl of each solution. After development, dry the plate in air, spray with ninhydrin solution and heat at 100° for 10 minutes. The principal spot in the chromatogram obtained with the test solution corresponds to that in the chromatogram obtained with the reference solution.

1. In the assay, the principal peak in the chromatogram obtained with the test solution corresponds to that in the chromatogram obtained with the reference solutions.

5.0)      Hardness:

The standard method used for tablet hardness testing is compression testing. The tablet is placed between two jaws that crush the tablet. The machine measures the force applied to the tablet and detects when it fractures. Although compressive force is applied to the tablet, along the diameter of the tablet at right angles to the applied force.

6.0)      Disintegration Time

Unless otherwise stated in the individual monograph, introduce one tablet into each tube and add a disc to each tube. The assembly is suspended in the liquid medium in a suitable vessel, preferably a 1-litre beaker. The volume of liquid is such that the wire mesh at its highest point is at least 15mm below the surface of the liquid, and at its lower point is at least 25mm above the bottom of the beaker. At no time should the top of the basket-rack assembly become submerged. There is a thermostatic arrangement for heating the liquid and maintaining the temperature at 37±2°.

If 1 or 2 tablets fail to disintegrate, repeat the test on 12 additional tablets; not less than 16 of the total of 18 tablets tested disintegrate.

If the tablets adhere to the disc and the preparation under examination fails to comply, repeat the test omitting the disc. The preparation complies with the test if all the tablets in the repeat test disintegrate.

7.0)      Dimension of Tablet:

Length, breadth and thickness are determined by vernier in mm

8.0)      Friability:

The test is applicable to compressed tablets and is intended to determine the physical strength of tablets. Tablets with a unit weight equal to or less than 650 mg, take a sample of whole tablets corresponding as near as possible to 6.5g. For tablets with a unit weight of more than 650mg, take a sample of 10 whole tablets. The tablets should be carefully dedusted prior to testing. Accurately weigh the tablet sample, and place the tablets in the drum. Rotate the drum 100 times and remove the tablets. Remove any loose dust from the tablets as before, and accurately weigh.

The test is run only once unless the results are difficult to interpret or if the weight loss is greater than the target value, in which case, the test is repeated twice and the mean of the three tests is determined.

Formula: initial wt. – after friability wt. x100 / initial wt.

A maximum loss of weight (From a single test or from the mean of three tests) not greater than 1.0 percent is acceptable for most tablets.

9.0)      Dissolution:

Medium: 900ml of 0.01 M Hydrochloric acid

Time: 45 minutes

Speed: 50 rpm

Limit: NLT 75% of the stated amount of Baclofen.

Withdraw a suitable volume of the medium and filter.

Determine by liquid chromatography.

Test solution: Use the filtration as given below.

Reference solution: A 0.001 per cent w/v solution of baclofen reference standard in the dissolution medium.

Chromatographic system:

• A stainless steel column 20cmX4.6mm packed with octadecylsilyl silica gel (10µm) (such as Nucleosil C18)
• Mobile phase: 0.01M sodium hexanesulphonate in a mixture of 100 volumes of methanol, 100 volumes of water and 1 volumes of G.A.A.
• Flow rate: 2ml per minute,
• Spectrophotometer set at 265nm,
• Injection volume: 20µl

Calculate the content of baclofen in the medium.

10.0)    Leak test:

The apparatus is used to test for the integrity of packed strips, blisters and Alu-Alu Blister pack containing tablets. Ensure apparatus bath is filled with purified water upto mark indicated and add 0.5% crystal violet solution in water. Samples are placed into the desiccators and the lid is placed in position. The pump starts to produce a vacuum 15inHg inside the desiccators and the vacuum is held for 1 minute. The sample remains at the required vacuum level for given time interval buzzer will sound after time is over and will cut off the vacuum pump. As the package is immersed in a colored dye solution the venting of the desiccators will allow any holes to be penetrated by the dye and the contents of the flexible packaging will also be stained with the same coloring material.

Examine all the strips for any leakage by opening the pockets manually. If anyone pocket shows evidence of leakage, reject the sample, stop the Blister / Strip machine and immediately take corrective action.

10.0)    Lactam: Determined by liquid chromatography.

Test solution: Mix with the aid of ultrasound a quantity of the powdered tablets containing 0.1 g of baclofen with 50ml of the mobile phase for 30 minutes, shaking occasionally to disperse the sample, and filter through a glass- fibre filter (such as whatman GF/C).

Reference solution (a): A solution containing 0.004 per cent w/v of (4RS)-4-(4-chlorophenyl) pyrrolidin-2-one reference standard (baclofen impurity A ) in the mobile phase.

Reference solution (b): A solution containing 0.2 per cent w/v of baclofen reference standard and 0.004 per cent w/v of (4RS)-4-(4-chlorophenyl) pyrrolidin-2-one reference standard (baclofen impurity A) in the mobile phase.

Chromatographic system:

• A stainless steel column 25cmX4.6mm packed with octadecylsilane bonded to porous silica (10µm),( such as spherisorb ODS 1)
• Mobile phase: a mixture of 5 volumes of glacial acetic acid, 440 volumes of methanol and 560 volumes of water containing 1.822g per litre of sodium hexanesulphonate
• Flow rate: 2ml per minute,
• Spectrophotometer set at 266nm,
• Injection volume: 20µl

Inject reference solution (b). The test is not valid unless the resolution between the peaks due to baclofen and baclofen impurity A is at least 2.0.

Inject reference solution (a) and the test solution. In the chromatogram obtained with the test solution the area of any peak corresponding to baclofen impurity A (lactam) is not greater than the area of the peak in the chromatogram obtained with the reference solution (2.0 per cent).

11.0)    Assay: Determined by liquid chromatography.

Test solution: Add a quantity of whole tablets containing 0.1 g of baclofen to 25ml of a mixture of 100 volumes of water and 1 volume of glacial acetic acid and disperse with the aid of ultrasound. Dilute to 50.0ml with methanol, filter and use the filtration.

Reference solution: A 0.2 per cent w/v solution of baclofen reference standard in a mixture of 100 volumes of methanol, 100 volumes of water and 1 volume of glacial acetic acid.

Chromatographic system:

• A stainless steel column 20cmX4.6mm packed with octadecylsilyl silica gel (10µm) (such as Nucleosil C18)
• Mobile phase: 0.01M sodium hexanesulphonate in a mixture of 100 volumes of methanol, 100 volumes of water and 1 volumes of G.A.A.
• Flow rate: 2ml per minute,
• Spectrophotometer set at 265nm,
• Injection volume: 20µl

Inject the reference solution. The test is not valid unless the relative deviation for replications is not more than 2.0 per cent.

Calculate the content of Baclofen in tablets.

Alternative Method: By UV Spectrophotometer

Test Solution: Weigh and powder 20 tablets. Weight sample equivalent to 10mg of Baclofen 100ml volumetric flask add 20ml methanol into it and sonicate to dissolve the test sample. Make up to mark with methanol. Filter and dilute 5ml to 50ml with 0.1 M HCl.

Reference Solution: Weigh 50mg of reference standard of Baclofen in 100ml of volumetric flask. Add 20ml methanol into it and sonicate to dissolve. Make up to mark with mrthanol. Dilute 1ml of this solution to 50ml with 0.1 M HCl.

Check Absorbance of test as well as reference standard at about 220nm in UV Spectrophotometer.

Calculate the content of Baclofen in the tablets.

Formula:

Area of Test      STD Wt.(mg)  1              100                50          Potency

—————–X————–X——-X——————X——–X———–X Average wt.

Area of STD        100              50        Test Wt.(mg)      5            100

Acceptance criteria: 90.0%-110.0%

13.0)    MICROBIOLOGICAL PURITY

Perform the test according to requirements of IP,

Total aerobic Microbial count (TAMC): NMT 103 CFU/g

Total combined yeasts/Moulds count (TYMC): NMT 102 CFU/g

Pathogens: in 1gm drug.

Escherichia Coli – Should be absent

Pseudomonas aeroginosa – Should be absent

Salmonella – Should be absent

Staphylococcus aureus– Should be absent

Abbreviations:

Wt.: Weight

mg: Miligram

ml: Milileter

STD: Standard

inHg: Inch of Mercury

rpm: Rounds per minute

CFU: Colony forming unit

O.P.A: Orthophosphoric acid

HCl: Hydrochloric acid