Ajibola A. Olaniyi

A new spectrophotometric method for the determination of nadolol

A new spectrophotometric method has been developed for the assay of nadolol in pure form and in tablets. The assay procedure is based on a derivatization methodology employing 4-carboxyl-2,6-dinitrobenzene diazonium ion (CDNBD) as a diazo coupling reagent. The azo dye formed between nadolol and CDNBD absorbed visible light at the wavelength maximum of 416 nm (λmax) demonstrating a bathochromic shift from the absorption maximum of nadolol. Optimization studies established an optimal reaction time of 10 min at 60 °C. The assays were linear over 1.25–10 μg ml−1 of nadolol, and the reaction occurred by a 3:1 reagent/drug stoichiometric ratio. The method is found to be selective and has a lower detection limit of 0.29 μg ml−1. Recovery studies over three days gave mean recovery of 101.4% (RSD 3.0%). This new method has been successfully applied in the determination of nadolol and nadolol/bendroflumethiazide tablets with accuracy and precision similar to the official (USP) HPLC procedure (p > 0.05). The new procedure has the advantages of high sensitivity, lower limit of detection and could find application as an in-process quality control method for nadolol.

Effect of proguanil interaction on bioavailability of cloxacillin

Methods:  To investigate a potential drug–drug interaction between proguanil (PG) and cloxacillin (Clox). Seven healthy adult volunteers received a single oral dose of Clox plus coadministration of single oral doses of PG and Clox in a simple cross‐over manner after a wash‐out period of 1 week. Total urine voided was collected at predetermined time intervals over 12 h. Amount of Clox in urine was determined by a reversed‐phase high‐pressure liquid chromatography method.

Effect of fluconazole on the pharmacokinetics of halofantrine in healthy volunteers

Background:  Halofantrine, an antimalarial drug used in endemic areas such as the tropics is mainly metabolized by CYP3A4 to the active metabolite N‐desbutylhalofantrine. Fluconazole, an antifungal agent and an inhibitor of CYP3A4 is an established part of the therapy in HIV patients, who in turn are prone to malaria in the tropics. This study investigated the effect of fluconazole on the pharmacokinetics of halofantrine after concurrent administration of the two drugs.