1.0) Description: Visual

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

Average weight of tablet contents Percentage deviation
80 mg or less ± 10 %
More than 80 mg but less than 250 mg ±7.5 %
250 mg or more ±5 %

4.0) Identification:

The absorbance of the assay preparation corresponds to that of the standard preparation.

5.0) Disintegration Test: Unless otherwise stated in the individual monograph, introduce one tablet into each tube and add a disc to each tube. Suspend the assembly in the beaker containing about 900 ml of water and operate the apparatus for the specified time. Remove the assembly from the liquid. The tablets pass the test if all of them have disintegrated.     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 being examined fails to comply,   repeat the test omitting the discs. 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) Assay of active ingredients:

 (A) Calcium Carbonate IP Elemental Calcium :-  By Titration Method.


  1. Dilute Hydrochloric acid
  2. Calcon ( as an indicator )
  3. 10% Sodium Hydroxide solution

Procedure: Weigh a quantity eq to 50 mg of calcium carbonate. Add 3 ml of dilute Hydrochloric acid  and 10 ml of water. Heat the solution for 5 minutes and then cool and dilute to 50 ml with water. Titrate with 0.05 M EDTA to within a few ml of the expected end point. Add 8 ml of 10% Sodium hydroxide solution. Add 0.1 gm of calcon mixture and continue the titration until the colour of the solution changes from pink to blue colour.

1 ml of 0.05 M EDTA is eq to 2.004 mg of Calcium.


Calcium :           Volume used x Normality x factor x Avg.wt.

0.05 x sample weight

(B)   Zinc Sulphate eq. to Elemental zinc: 22.5mg/tab By UV-Method: 

Reagent:  Dithizone regent: 50 mg dithizone in 100 ml chloroform

Standard Dilution: Take 50 mg of standard in 100 ml of volumetric flask. Add 50 ml of water and Sonicate for 10 minutes and make up the volume upto 100 ml with water. Take 5 ml of this solution and dilute to 50 ml with water.

Sample Dilution: Weigh a quantity eq to 50 mg of sample in 100 ml of volumetric flask. Add 50 ml of water and Sonicate for 10 minutes and make up the volume upto 100 ml with water. Filter the solution and take 5 ml of this solution and dilute to 50 ml with water.

Procedure:  Take 5 ml sample and standard dilution in different separating funnel and add 5 ml water and add 25 ml dithizone regent and shake for 2 minutes and separate chloroform layer in 25 ml volumetric flask. Take reading on spectrophotometer at 550 nm.


Abs.of Test          STD Wt.(mg)       5                 100                  50        Potency

——————–X——————X———X——————–X———-X———–X   Avg.wt.

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


(C) Vitamin D 3:  By HPLC method. 

[Mobile phase: HPLC grade Methanol]

Column: C18 (250mm x 4.6 micr.)

UV- wavelength:  265 nm

Flow/rate: 1.0 ml/min.

Standard preparation: 

Weigh 35 mg of vitamin D3 working standard in 50 ml Volumetric flask and add 25 ml of HPLC Grade Methanol and Sonicate for 10 minutes and make up to the mark with HPLC Grade methanol.

Test Preparation: Weigh a quantity eq to Average weight of sample in a 100 ml of volumetric flask. Add 50 ml of HPLC Grade methanol and Sonicate the solution for 10 minutes. After that make the volume upto mark with HPLC Grade Methanol. Filter the solution and inject the replicates of injections.


Area of Test                  STD Wt(mg)             100

Vitamin D3    ————————–X——————-X——————-Xavg. Wt,

Area of STD                          50                     Test Wt.