Validation of Amoxicillin iodometric procedure in quantitative analysis of pure substance and medical preparation

Abstract

The aim of the work is to validate a simple and rapid iodometric procedure for the quantitative determination of amoxicillin in pure substance and medicinal preparation using potassium caroate as analytical reagent. Materials and methods. The procedure involves the use of potassium caroate (KHSO5) as an oxidant. The assay is based on the quantitative penicillin oxidation by KHSO5 to the corresponding S-oxide. The interaction between amoxicillin and analytical reagent is stoichiometric. Indirect iodometric method is used for the quantitative determination of amoxicillin main substance. The validation procedure was performed according to the State Pharmacopeia of Ukraine. Results. The precision, accuracy, limit of detection (LOD), and limit of quantitation (LOQ) are accepted over the concentration range of 80–120 % with a correlation coefficient of 0.999. LOD and LOQ were found to be 4.91 % and 14.73 % for amoxicillin pure substance respectively. The precision calculated as the relative standard deviation (RSD) was less than 0.8 % and accuracy (δ, relative error) was better than 0.4 %. The proposed method was validated statistically and through recovery studies. For Amoxicillin medical preparation RSD ≥1.93 % and δ ≥ 1.62 %. Conclusions. The obtained data showed acceptable agreement with the certificate results, so the proposed procedure can be used for the assay of amoxicillin in medicinal preparation.