• Description: Visual
  • Average Weight: Check weight of 20 tablets at random and calculate the average weight by formula.

Average weight (mg) =   wt of 20 tablets (gm) x 1000


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.

Weigh the tablets individually and calculate the percentage of deviation for each tablet by using formula.

Deviation(%)= (experimental weight – theoretical weight)    x 100

Theoretical weight


Average weight of tablets Percentage deviation
250mg or More 5%

4.0)      Identification Test:

In the assay, the retention time of the principal peaks in the chromatogram obtained with the test solution corresponds to the peak in the chromatogram obtained with the reference solution.

5.0)      Disintegration Test:

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.

6.0)      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.

7.0)      Dimension of Tablet:

Length, breadth and thickness are determined by vernier calliper 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 6.5 g. 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.

% Friability = W1 – W2 X 100


W1= Initial weight                  W2= Final weight

            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.

If obviously cracked, chipped or broken tablets are present in the sample after tumbling, the sample fails the test.

9.0)      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 up to 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)    Assay:

            Determined by liquid chromatography:

Standard solution: Weigh accurately about 162.5 mg of Paracetamol reference standard, and 50 mg of Aceclofenac reference standard and 125 mg Chlorzoxazone reference standard in 100ml volumetric flask, dissolve in and dilute to the mark with mobile phase. Shake well and further dilute 2 ml to 25 ml with mobile phase. Shake well and filter through 0.45µm nylon filter.

Test Solution: Weigh accurately about equivalent to 162.5 mg of Paracetamol from crushed powder of  20 tablets in 100 ml volumetric flask, add 50 ml of mobile phase, sonicate for 5 minutes, cool to room temperature and dilute to the mark with mobile phase, filter. Shake well and further dilute 2 ml to 25 ml with mobile phase, shake well and filter through 0.45µm nylon filter.

Procedure: Inject separately standard and test preparation. Inject five replicate injection of working standard and two replicate injection of test preparation. RSD of replicate injection should not more than 2%. Calculate the assay of Paracetamo, Chlorzoxazone and Aceclofenac by comparison to peak area of standard preparation.

            Chromatographic system:

  • A stainless steel column (25cm X4.6mm,) C18
  • Mobile phase: Methanol :Water and G.A.A. (80: 20) and (0.01ml); degas
  • Flow rate: 1.2ml per minute,
  • Spectrophotometer set at 280nm,
  • Injection volume: 20µl

Inject the reference solution and test solution.

Calculate the content of Paracetamol, Chlorzoxazone and Aceclofenac in tablets.


Area of Test      STD Wt.(mg)   2           100                25       Potency

—————–X————–X———-X—————–X——X———–X   Average weight

Area of STD        100               25      Test Wt. (mg)     2        100

            Acceptance criteria: 90.0%-110.0%