Journal of Pharmaceutical and Biomedical Analysis 21 (1999) 881–886 Short communication Electrochemical study on the determination of tinidazole in tablets Ali Z. Abu Zuhri a, *, Suleiman Al-Khalil b , Raqi M. Shubietah c , Ibrahim El-Hroub a a Chemistry Department, An -Najah National Uniersity, Nablus, P.O. Box 707, Palestine b Medical Technology Department, An -Najah National Uniersity, Nablus, P.O. Box 707, Palestine c Faculty of Pharmacy, An -Najah National Uniersity, Nablus, P.O. Box 707, Palestine Received 12 November 1998; received in revised form 9 June 1999; accepted 27 June 1999 Abstract The electrochemical reduction of tinidazole has been carried out in aqueous solution in the pH range 1.8 – 11.3 by differential-pulse (DP) polarography. Tinidazole exhibits one or two reduction peaks depending on pH. In strongly acidic solution (pH 4.5), one reduction peak was obtained and it was suitable for analytical purposes. A method for the determination of tinidazole by DP polarography in Britton – Robinson buffer of pH 3.0, which allows quantifica- tion over the range 0.03–7.30 g/ml, was proposed. The method was successfully applied to the determination of tinidazole in tablets with mean recovery and relative standard deviation of 98.7 and 3%, respectively. Excipients did not interfere in the determination. © 1999 Elsevier Science B.V. All rights reserved. Keywords: Tinidazole determination; Differential-pulse polarography; Pharmaceutical formulations www.elsevier.com/locate/jpba 1. Introduction Tinidazole (TNZ) is a 5-nitroimidazole deriva- tive which is highly effective as a treatment for Giardiasis. The oral single doze of TNZ is equiva- lent to a 3-day therapy with metronidazole with- out substantial side effects [1]. Several methods have been reported for the determination of TNZ, including spectrophoto- metry [2–5] and chromatography [6–9]. Little attention has been paid to the determination of TNZ using the electrochemical techniques [10,11]. The electrochemical techniques have been success- fully applied for the determination of some phar- maceutical formulations and biological fluids [12–14]. On the other hand, there is no official method that has been adopted in the pharmaco- poeias for the determination of TNZ. * Corresponding author. Fax: +972-9-238-7982. E-mail address: abuzuhri@najah.edu (A.Z. Abu Zuhri) 0731-7085/99/$ - see front matter © 1999 Elsevier Science B.V. All rights reserved. PII:S0731-7085(99)00201-0