Application of densitometry for determination of beta-adrenergic-blocking agents in pharmaceutical preparations

Abstract

A chromatographic-densitometric method has been established for identification and quantitation of selected beta-adrenergic-blocking agents in pharmaceutical preparations. Retention factors, RF , and characteristic absorption spectra of 11 drugs chromatographed on silica gel 60 F 254 HPTLC plates with six mobile phases were used for identification. Quantitation and validation of the method was performed for atenolol, acebutolol, propranolol, and bisoprolol using chloroform-methanol-ammonia, 15 + 7 + 0.2 ( v/v ), as mobile phase. UV densitometric measurements were performed at the wavelength of maximum absorption. Pharmaceutical preparations used in medicine and from a variety of manufacturers were analyzed and the method shown to be sufficiently sensitive for analysis of these samples. The limits of detection and determination ranged from 30 to 400 ng and recovery was from 97.14 to 102.18%. The precision of the method, described by the equation y = xmean ± 2 S , is good and the range of linearity is wide — from 0.020 to 0.250% for individual constituents.