Spectrophotometric Methods for the Determination of Anti-diabetic Drug Glipizide in Pure and Pharmaceutical Formulations

摘要

Four simple and precise spectrophotometric methods were developed and optimized for the assay of glipizide (GPZ) in pure form and in its pharmaceutical preparations. Method A was based on the reaction of drug with 1,2-naphthoquinone-4-sulfonate (NQS) in alkaline medium to form orange colored product (λ_max 456 nm). In the method B, drug reduced the reagent tetrazolium blue (TB) which lead to the formation of intense violet colored formazan (λ_max 515 nm). The method C employed Folin-Ciocalteu reagent (FC) that reacted with drug in alkaline medium to form blue colored complex (λ_max 760 nm). Method D was based on the reduction of iron(III) to iron(II) by the drug and their complexation with bathophenanthroline (BPT) to form pink colored complex (λ_max 547 nm). Linearity of Beer’s plots was observed in the concentration range of 10.00 – 100.00 µg mL-1, 2.00 – 22.00 µg mL-1, 5.00 – 40.00 µg mL-1, 0.50 – 7.50 µg mL-1 for method A, B, C and D respectively. The proposed methods were validated and values of analytical parameters like molar absorptivity, Sandell’s sensitivity, limits of detection and quantification were also calculated. The methods were found to be selective for the quantitative determination of GPZ in commercially available formulations.