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:
Dissolve the powdered tablet containing about 0.1gm of Betahistine Hydrochloride in 5ml of water, add 0.5ml of 5M sodium hydroxide, extract with 5ml of dichloromethane, filter the dichloromethane layer through anhydrous sodium sulphate with 2ml of dichloromethane and evaporate the solution to dryness. The residue complies with the following test
- Determine by infrared absorption spectrophotometry. Compare the spectrum with that obtained with betahistine hydrochloride reference standard treated in the same manner or with the reference spectrum of betahistine.
- In the Assay, the principal peak in the chromatogram obtained with the test solution corresponds to the peak in the chromatogram obtained with the reference solution.
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:
Apparatus: Basket
Medium: 900ml of buffer solution prepared by dissolving 21.9gm of anhydrous disodium hydrogen orthophosphate and 4.83gm of citric acid in 1000ml of water, adjust the pH to 6.8 with 1M sodium hydroxide.
Time: 30 minutes
Speed: 50 rpm
Withdraw a suitable volume of the medium and filter. Measure the absorbance of the filtered solution, suitably diluted with the medium if necessary, at the, maximum at about 256nm. Calculate the content of Betahistine DiHCl in the medium from the absorbance obtained from a solution of known concentration of betahistine HCl in the same medium.
Limit: NLT 85% of the stated amount of Betahistine DiHCl.
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.
11.0) Related substance: Determined by liquid chromatography.
Test solution: Disperse a quantity of powdered tablets containing 32mg of betahistine dihydrochloride in 50ml of mobile phase and dilute to 100ml with mobile phase, centrifuge and use the supernatant liquid.
Reference solution (a): Dilute 1.0mlof the test solution to 500ml with mobile phase.
Reference solution (b): A 0.00064 per cent w/v solution of betahistine impurity C reference standard (N-methyl-2-(pyridine-2-yl)-N-[2-(pridine-2-yl) ethyl]ethanamine trihydrochloride) in the mobile phase.
Reference solution (c): A 0.000032 per cent w/v solution of betahistine impurity A reference standard (2-vinylpyridine) in acetonitrile.
Reference solution (d): A solution containing 0.00064 per cent w/v each of betahistine impurity C reference standard and betahistine dihydrochloride reference standard in the mobile phase.
Chromatographic system:
- A stainless steel column 25cmX4.6mm packed with octadecylsilane bonded to porous silica (5µm) (such as Zorbax XDB Eclipse),
- Mobile phase: Dissolve 0.4 gm of hexylamine in 600ml of a solution containing 0.46 per cent w/v solution of sodium dihydrogen orthophosphate monohydrate and 0.27 per cent w/v of sodium lauryl sulphatre, add 400ml of acetonitrile, mix and adjust the pH to 3.5 using O.P.A.
- Flow rate: 2ml per minute,
- Spectrophotometer set at 254nm,
- Injection volume: 20µl
Inject reference solution (d). The test is not valid unless the resolution between the peaks due to N-methyl-2-(pyridine-2-yl)-N-[2-(pridine-2-yl) ethyl]ethanamine trihydrochloride and betahistine dihydrochloride is not less than 3.0.
Inject reference solutions (a), (b), (c) and the test solution. Run the chromatogram 4 times the retention time of the principal peak. In the chromatogram obtained with the test solution, the area of any peak corresponding to betahistine impurity C is not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (2.0 per cent) and the area of any peak corresponding to betahistine impurity A is not more than twice the area of the principal peak in the chromatogram obtained with reference solution
(c) (0.2 per cent). The area of any other secondary peak is not more than the area of the principal peak in the chromatogram obtained with reference solution
(a) (0.2 per cent) and the sum of the areas of all the secondary peaks is not more than 10 times the area of the principal peak in the chromatogram obtained with reference solution (a) (2.0 per cent). Ignore any peak with an area less than 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (c) (0.05 per cent).
12.0) Uniformity of content: Determine by liquid chromatography, as under assay.
Test solution: Disperse one tablet to a 25ml volumetric flask with about 15ml of mobile phase, mix with aid of ultrasound and dilute to 25ml with the mobile phase, filter. Dilute with mobile phase to achieve concentration of 0.032 per cent w/v of betahistine hydrochloride.
Calculate the content of betahistine DiHCl in the tablet.
13.0) Assay: Determined by liquid chromatography.
Test solution: Weigh and powder 20 tablets. Weight a quantity of the powdered tablet containing 32mg of Betahistine DiHCl, disperse in 50ml of mobile phase and dilute to 100ml with mobile phase and filter.
Reference solution: A 0.032 per cent w/v solution of betahisine dihydrochloride reference standard in mobile phase.
Chromatographic system:
- A stainless steel column 25cmX4.6mm packed with octadecylsilane bonded to porous silica (5µm),
- Mobile phase: dissolve 2.7gm of sodium dihydrogen orthophosphate monohydrate and 1.6gm of sodium dodecylsulphate in 600ml water. Add 0.4 gm of hexylamine and 400ml of acetonitrile, adjust the pH to 3.5 using O.P.A.
- Flow rate: 2ml per minute,
- Spectrophotometer set at 254nm,
- Injection volume: 20µl
Inject reference solution. The test is not valid unless the tailing factor is not more than 2.0. The column efficiency is not less than 2000 theoretical plates. The relative standard deviation for replicate injections is not more than 2.0 per cent.
Inject reference solution and the test solution.
Calculate the content of Betahistine Dihydrochloride in the tablet.
Formula for calculation:
Area of test Weight of STD 100
—————- X————————X——————— X Average weight X Potency of STD
Area of STD 100 Weight of test
Alternative Method: By UV Spectrophotometer
Test Solution: Weigh and powder 20 tablets. Weight sample equivalent to 25mg of betahistine dihydrochloride in 100ml volumetric flask add some 0.1 M HCl into it and sonicate to dissolve the test sample. Make up to mark with 0.1M HCl. Filter and dilute 2ml of this solution to 50ml in same solvent.
Reference Solution: Weigh 25mg of reference standard of betahistine dihydrochloride in 100ml of volumetric flask. Add some 0.1 M HCl into it and sonicate to dissolve. Dilute 1ml of this solution to 50ml with same solvent.
Check Absorbance of test as well as reference standard at about 261nm in UV Spectrophotometer.
Calculate the content of Betahistine Dihydrochloride
Formula:
Area of Test STD Wt.(mg) 1 100 50 Potency
—————–X————–X——-X—————X——–X———–X Average weight
Area of STD 50 50 Test Wt.(mg) 2 100
Acceptance criteria: 95.0%-105.0%
14.0) 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
OPA: Orthophosphoric acid
