Assay Method (U-Z)

Assay Method of
 Ursodeoxycholic Acid Tablet

Sample

Take average weight of 20 tablet and crush in a mortar to achieve fine powder. Take equivalent amount of tablet powder containing 150 mg of Ursodeoxycholic Acid in 50 ml Ethanol R into 250ml titration vessel, previously neutralized to 0.2 ml of phenolphthalein solution R. Add 50 ml of Distilled Water and Titrate with 0.1M Sodium Hydroxide VS until a pink color is obtained. Each ml of 0.1M Sodium Hydroxide VS is equivalent to 39.26 mg of Ursodeoxycholic Acid.

  Assay Method of
 Valdicoxib Tablet

Buffer	Dissolve about 3.854 g of Ammonium Acetate in 900 ml water. Adjust pH to 5.0±0.05 with dilute acetic acid and dilute to 1000 ml with water.
Ratio	Mix 50 volume of Buffer with 50 volume of methanol and filter through a 0.45-micron membrane filter and degas.
Standard	Dissolve about 25.0 mg of valdicoxib WS in 50 ml of methanol and dilute to 100 ml with water. Dilute 5 ml to 50 ml with mobile phase. Filter this solution with 0.45 m membrane filter before injection.
Sample	Shake a quantity of the powdered sample containing about 25.0 mg of Valdicoxib in 50 ml of methanol for 30 minutes, dilute to 100 ml with water and then filter. Dilute 5 ml of filtrate to 50 ml with mobile phase. Filter this solution with 0.45 m membrane filter before injection.
Condition	C18 Column (4.6 mmx 25cm) & 10µm (ODS1)./ UV at 245 nm

Assay Method of
 Valproic acid + Sodium Valproate Tablet

For Valproic Acid

Sample

Weigh & take the average weight of 20 tablets. Crush the tablets into fine powder. Take a quantity of the powder containing equivalent to 58 mg of Valproic acid into a 200 ml volumetric flask. Add accurately 100 ml of ethanol 96%. Shake for 20 minutes & filter. Take 50 ml of filtrate solution in 100 ml conical flask & add 1 ml of 1% Phenaphaline solution as indicator. Titrate with 0.1M Sodium hydroxide VS to a pink color end point. Perform blank titration for necessary correction. Each ml of 0.1M Sodium hydroxide VS  º 14.42 mg of Valproic Acid

 \ Content of Sodium valproate (C₁) in mg º  ( 87 x % of Valproic acid ) x 1.1517           

For Sodium Valproate

Sample

Weigh & take the average weight of 20 tablets. Crush the tablets into fine powder. Take a quantity of the powder containing equivalent to 66.8 mg of Sodium valproate into a 100 ml glass vessel. Add 60 ml of glacial acetic acid & shake for 20 minutes. Titrate with 0.1M Perchloric Acid vs using     crystal violet solution as indicator. Perform blank titration for necessary correction. Each ml of 0.1M Perchloric Acid VS  º 16.62 mg of Sodium valproate.

                                              

Assay Method of
 Verapamil Hydrochloride Tablet

                             .

Sample	Shake a quantity of the powder containing 100 mg of Verapamil Hydrochloride with 150 ml  of  0.1 M  hydrochloric  acid for 10 minutes;  add sufficient 0.1 M hydrochloric acid to produce 200 ml and filter. Dilute 10 ml of the filtrate to 100 ml with water.Measure the absorbance of the resulting solution at the maximum at 278 nm using 0.1 M hydrochloric acid as blank.
Calculation	% of Verapamil Hydrochloride=Absorbance of Sample´100/Conc. Of spl.´118

Assay Method of
 Vinpocetine Tablet

Solvent	Chloroform
Standard	50 mg ----® 100 ml ----® take 5 ml ----® 50 ml  (Shake 20 minutes)
Sample	Same as standard. Take absorbance at 336 nm.

Assay Method of
 Zinc (Elemental) Syrup

Sample

Take 35 ml of Nid Syrup equivalent to about 70 mg of Elemental Zinc (35ml) in a 250 ml conical flask. Add 100 ml distilled water & mix well. Then add 5 ml of Ammonia - Ammonium Chloride buffer TS and using 0.1 ml of Erio-Chrome Black TS as   indicator. Titrate immediately with 0.05M Na2EDTA VS. At the end point the solution become violet to deep blue. Each ml of 0.05M Na2EDTA VS is equivalent to 3.269 mg of elemental Zinc. % of Zinc =    Required Vol. Of VS x Constant x F x 100 / Weight of Elemental Zinc in sample Solution