Journal of Pharmacological Methods 1985-06-01

Application of Azure C for the extractive spectrophotometric determination of microgram amounts of penicillin.

A T Gowda, N M Gowda, H S Gowda, K S Rangappa

Index: J. Pharmacol. Methods 13(3) , 275-80, (1985)

Full Text: HTML

Abstract

A simple, accurate, and rapid method for the quantitative determination of penicillin is proposed. The method is based on the formation of a blue penicillin-Azure-C ion-pair that can be extracted into chloroform in phosphate-citric acid buffer. The molar absorptivities for sodium penicillin G and potassium penicillin V at 635 nm were 5.46 X 10(3) and 2.19 X 10(4) l/mol/cm, respectively. Beer's law was valid over the concentration range of 4-80 micrograms/ml for sodium penicillin G and 3-55 micrograms/ml for potassium penicillin v. Maximum absorbance was obtained almost instantaneously and was stable for several days. The method was successfully applied to pharmaceutical preparations.