Pharmaceutical Salt Calculation

Question

Glucosamine is common dietary supplement for arthritis and joint health and is supplied either as sulfate or hydrochloride salt. Schiff’s Glucosamine tablets contain 1500mg glucosamine HCl, and Spring Valley’s Glucosamine tablets contain 1500mg glucosamine sulfate. How much glucosamine is in a Schiff and Spring Valley’s Glucosamine tablet? Glucosamine MW=179.2 HCl MW = 36.5 H2SO4 = 98

 

Answer 1

Molar mass of glucosamine HCl = 179.2 + 36.5 = 215.7 g/mol

% glucosamine = 179.2 g / 215.7 g x 100% = 83.1% glucosamine

mg of glucosamine in Schiff tablets = 1500 mg x 83.1% glucosamine = 1247 mg (1250 mg to 3 sig.figs.)

Molar mass glucosamine sulfate = 179.2 + 98 = 277.2 g/mol

% glucosamine = 179.2 / 277.2 x 100% = 64.6% glucosamine

mg glucosamine in Spring Valley tablets = 1500 mg x 64.6% = 969 mg glucosamine