A Simple Liquid Chromatographic Method for Estimation of Glycopyrrolate in Pharmaceuticals Using Experimental Design

A liquid chromatographic method was developed and validated to estimate glycopyrrolate (GLP) present in pharmaceutical formulations. The method was developed using a C18 column with a mobile phase involved methanol: phosphate buffer (pH=3.2) (65:35, %v/v) flowing at 1.0ml min-1. GLP was detected at a wavelength of 224nm. The method was found linear over a concentration range of 6-14µg ml-1. Degradation studies proved the chromatographic method specificity. Validation studies postulated method acceptability and suitability for estimating GLP in both bulk as well as injectables. The detection and quantitation limits were 2.5µg ml-1 and 6.0µg ml-1, respectively. Further, method precision was assured (%R.S.D. <2%) employing an experimental design approach using a factorial design. Also, it revealed that analyst skills are of critical importance and may influence the method preciseness. Overall the method was reliable and of optimum quality and possesses the potential of application in routine quality control of dosage forms of GLP and may serve as a basis for future bio-analytical method development purpose.