1.0) Description: Visual

2.0) 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 (%) =  Weight of each tablet – Average weight    x 100

Average weight

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

4.0) Identification Test:

1)         Calcium Carbonate: Dissolve 5 gm in 80 ml of 2 M acetic acid. When effervescence ceases, boil the solution for 2 minutes, allow to cool, dilute to 100 ml with 2 M acetic acid and filter, if necessary, through a sintered glass filter reserving any residue for the test for substances insoluble in acetic acid; the filtrate gives reaction A and B of calcium salts.

2)         Magnesium Hydroxide: Dissolve about 15 mg in 2 ml of 2 M Nitric acid and neutralize with 2 M Sodium hydroxide. The resulting solution gives the reaction of magnesium salts.

3)         Vitamin D3: In the assay, the principal peak in the chromatogram obtained with the test solution corresponds to that in chromatogram obtained with the reference solution.

4)         Zinc Sulphate Monohydrate: In the assay, the chromatogram obtained with the test solution corresponds to 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.

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 15 mm below the surface of the liquid, and at its lower point is at least 25 mm 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  calliper in mm.

8.0)      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.

9.0)      Assay:

A.)       For Calcium carbonate Eq. to Elemental Calcium:

Weigh and powder 20 tablets. Weigh quantity of the powder containing equivalent to 50 mg of calcium add 5 ml of dilute HCl and 10 ml water. Heat the dispersion gently to boiling and continue to boil for about 2 minutes. Allow to cool and add 50 ml of water. Add 10 ml of 10% NaOH and calcon mixture as indicator and Titrate with 0.05 M EDTA until the colour of the solution changes from pink to a full blue colour.

Carry out a blank titration.

1 ml of 0.05 M disodium edetate is equivalent to 0.002004 g of Calcium.

           Calculation:     Volume Used X Normality of EDTA X 2.004 X Average Wt.

0.05 M  X Weight of Sample Taken

Acceptance criteria: 90.0%-110.0%

B.)       Assay of Magnesium Hydroxide Eq. to Elemental Magnesium:

Weigh accurately above crushed sample equivalent to 50 mg of Elemental Magnesium and transfer it into another conical flask. Add 25 ml of 1M Hydrochloric acid and heat it gently for five minutes. Sonicate it and dissolve it properly. Add 70 ml of water and add a little pinch of Eriochrome Black T indicator. Now add 20 ml of Ammonia-Ammonium Chloride buffer and titrate it with 0.05M EDTA Solution and also perform blank titration.

Note: Deduct the volume obtained in the titration of calcium from the volume obtained in titration of   Magnesium.

Calculation:       Volume used X Normality of EDTA X 2.916 X Average Wt. 

0.05 M X Weight of Sample taken

Note: Quantity of  Ammonia-Ammonium Chloride buffer can be increased or decrease for proper end point.

Acceptance criteria: 90.0%-110.0%

  • Assay of Zinc Sulphate Monohydrate Eq. to Elemental Zinc

Standard Preparation/ Sample Preparation: Prepare both standard and sample 50 mcg/ml in water.

Procedure: Take 5 ml of both standard and sample solution in two separating flasks. Add 50 ml of chloroform previously prepared by adding a small pinch of Dithizone Indicator. Shake it properly for 10 minutes. Resulting chloroform solution should be of pink colour.  Separate the chloroform and Filter the both standard and sample chloroform solution through cotton containing sodium sulphate.  Check the absorbance of both standard and sample solution between the wavelength 400 nm to 650 nm.

            Calculation : Test Abs   x   Std Wt.  x Average Wt. x Std . Potency

Std Abs         Test Wt.

Acceptance criteria: 90.0%-110.0%

D).       For Vitamin D3 (Cholecalciferol)

  Note: Use low-actinic glassware throughout the procedure.

Test solution: Weigh and powder 20 tablets. Disperse a quantity of powdered tablet equivalent to 0.1 mg of vitamin D3 in 170 ml of methanol by shaking for 5 minutes and mix with ultrasound for 5 minutes, dilute to 200.0 ml with methanol, mix and filter. Use the filtrate.

Reference solution: A 0.00005 per cent w/v solution of cholecalciferol reference standard in the methanol.

            Chromatographic system:

  • A stainless steel column 10 cm X 4.6 mm packed with octadecylsilane bonded to porous silica polymer (5µm)
  • Mobile phase: a mixture of 3 volumes of water and 97 volumes of methanol
  • Flow rate: 1ml per minute,
  • Spectrophotometer set at 264 nm,
  • Injection volume: 50 µl

Inject the reference solution and the test solution.

Calculate the content of Vitamin D3 in the tablet.

Acceptance criteria: N.L.T. 90.00%


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



Wt.: Weight

mg: Milligram

CFU: Colony forming unit

ml: Milliliter

inHg: Inch of Mercury

STD: Standard

Abs.: Absorbance

NaOH: Sodium Hydroxide