Flow injection analysis of vancomycin

Abstract

A flow injection method for the quantitative analysis of vancomycin hydrochloride, C66H75Cl2N9O24.HCl (HVCM), based on the reaction with copper (II) ions, is presented. HVCM forms a lilac-blue complex with copper ions at pH≅4.5 in aqueous solutions, with maximum absorption at 555 nm. The detection limit was estimated to be about 8.5×10-5 mol L-1; the quantitation limit is about 2.5×10-4 mol L-1 and about 30 determinations can be performed in an hour. The accuracy of the method was tested through recovery procedures in presence of four different excipients, in the proportion 1:1 w/w. The results were compared with those obtained with the batch spectrophotometric and with the HPLC methods. Statistical comparison was done using the Student's procedure. Complete agreement was found at a 0.95 significance level between the proposed flow injection and the batch spectrophotometric methods, which present similar precision (RSD: 2.1 % vs. 1.9%).

Flow Injection- Spectrophotometric Determination of Vancomycin Hydrochloride in Pharmaceutical Preparations Using Diazotized Metoclopramide

“…A survey of literature revealed that few methods based on visible spectrophotometry for VHC [5,6,7] have been reports. Other methods include HPLC [8,9,10,11], Polarography [12], Capillary electrophoresis [13], Radioimmunoa-ssay [14], Fluorescence polarization immunoassay [15] and Flow injection analysis [16,17]. This paper describes the batch and flow injection methods for spectrophotometric determination of vancomycin hydrochloride (VHC) by the diazotization-coupling reaction between VHC and diazotized metoclopramide (DMCP) in the presence of sodium hydroxide.…”