ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Method transfer assessment for boric acid assays according to different pharmacopoeias' monographs

Valentina Radulović, Branka Ivković, Nataša Bogavac-Stanojević, and Katarina Karljiković-Rajić

Department of Analytical Chemistry, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia

E-mail: valentina.radulovic@pharmacy.bg.ac.rs

Received: 2 June 2020  Accepted: 23 September 2020

Abstract:

Abstract

The background of this study was transfer assessment for H₃BO₃ assays according to different pharmacopoeias’ monographs and verification of the crucial parameters—the polyols’ excess (mannitol, glycerine, sorbitol), the initial H₃BO₃ concentrations and the indicator’s concentrations. The purpose of the work was the comparative study according to different pharmacopoeias: the European (EP 9), the American (USP 35-NF 30), the Japanese (JP XVII), important for quality control of H₃BO₃, as an active component or an excipient. pH analyses were set up to establish the effects of selected polyols and the initial H₃BO₃ concentrations. For evaluation of assay results and methods’ equivalence, standard t test and two one-sided t test (TOST) were applied. Pharmacopoeias’ procedures propose volumetric analyses by 1 M NaOH standard solution with visual end-point detection (phenolphthalein) using sufficiently high H₃BO₃ concentrations and less excess of polyols, as the good alternative to potentiometric method. The influence of phenolphthalein’s concentration (0.1%, 1%), evidenced as relevant factor, caused the difference shown by standard t test: 99.82% (EP 9) and 99.66% (JP XVII). Equivalences between three methods were confirmed by TOST procedures with defined acceptance criterion ± 2% derived from the mean value (99.83%). The comparative study results pointed out that the initial phenolphthalein’s concentration was the crucial influencing factor on harmonization of assay mean values, which was confirmed by TOST application for the methods’ equivalency in method transfer evaluation. The best possible correlation between the lowest excess of polyol-sorbitol and the highest initial boric acid concentration was proved by JP XVII, which was indicated by pH-metric analyses.

Graphic abstract

Keywords: Boric acid assay; Method transfer statistical evaluation; Comparative study; Pharmacopoeias; pH-metric analyses

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01377-x

Chemical Papers 75 (3) 1237–1246 (2021)