CARBOCISTEINE SYRUP 2%

Assay (by HPLC)

Standard preparation: Transfer accurately weigh about 100 mg of Carbocisteine WS in to a 100 ml volumetric flask, add 2 ml of 1M hydrochloric acid and 50 ml water, Sonicate for 2 minutes and shake for 5 minutes to dissolve and make up the volume to 100 ml with water and filter through Whatman filter paper No. 1.

Take 5 ml of the filtrate in to a 25 ml volumetric flask and make up the volume to 25 ml with mobile phase.    

Test preparation: Transfer an accurately measured quantity of liquid equivalent to about 100 mg of Carbocisteine in to a 100 ml volumetric flask, add 2 ml of 1M hydrochloric acid and 50 ml water, Sonicate for 5 minutes and shake for 10 minutes to dissolve and make up the volume to 100 ml with water and filter through Whatman filter paper No. 1.

Take 5 ml of the filtrate in to a 25 ml volumetric flask and make up the volume to 25 ml with mobile phase.    

Chromatographic system:

Mobile phase: Dissolve about 34.02 g of potassium dihydrogen phosphate (KH₂PO₄) in 1000 ml water; adjust pH 2.5 by orthophosphoric acid (H₃PO₄).

Mode: LC.

Detector: UV 220 nm.

Column: C₀₈ (3.9 cm x 150 mm), 5 µ (Kromasil) or equivalent.

Flow rate: 0.5 ml/Minute.

Column temperature: 25°C.

Injection volume: 20 µl.

Procedure: Separately inject equal volumes (about 20 µl) of the standard preparation and test preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks.

Calculation: Calculate the quantity of Carbocisteine in mg per 5 ml, by given below formula:

Average test area         Std. wt. (in mg)           5              100               25       Potency (in %)

—————————-x ————————x ——- x —————— x ——- x ———————- x 5 x wt./ml.

Average Std. area                   100                  25       test wt. (in g)        5               100