Journal of Pharmaceutical and Biomedical Analysis 45 (2007) 263–267 A high-performance liquid chromatography and nuclear magnetic resonance spectroscopy-based analysis of commercially available praziquantel tablets Jia Li a,b , Yulan Wang a , Alan Fenwick c , T. Andrew Clayton a , Yu Y.K. Lau d , Cristina Legido-Quigley e , John C. Lindon a ,J¨ urg Utzinger b , Elaine Holmes a,∗ a Department of Biomolecular Medicine, SORA Division, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK b Department of Public Health and Epidemiology, Swiss Tropical Institute, P.O. Box, CH-4002 Basel, Switzerland c Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, St. Mary’s Campus, Norfolk Place, London W2 1PG, UK d Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK e Pharmacy Research Division, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK Received 18 April 2007; received in revised form 30 May 2007; accepted 19 June 2007 Available online 23 June 2007 Abstract The amount of active ingredient in 20 commercially sourced batches of praziquantel (PZQ) tablets was determined using a high-performance liquid chromatography–ultraviolet (HPLC–UV) assay in conjunction with an anthentic, lot of PZQ powder. The general composition of each batch of tablets was also examined by means of 1 H nuclear magnetic resonance (NMR) spectroscopy and the NMR data were subjected to pattern recognition analysis by means of principal component analysis. The HPLC–UV results showed that each batch of PZQ tablets contained approximately the required amount of PZQ (600 mg per tablet). The NMR analysis showed a high degree of compositional variation between manufacturers, which caused by variation in excipients, along with some batch-to-batch variation in the tablets from a single manufacturer. Additionally, the PZQ tablets from one manufacturer were found to have an extra component (methyl-4-hydroxybenzoate) that was not detected in the other preparations. © 2007 Elsevier B.V. All rights reserved. Keywords: High-performance liquid chromatography; Nuclear magnetic resonance spectroscopy; Praziquantel; Principal component analysis; Quality control; Schistosomiasis 1. Introduction Praziquantel (PZQ) is the current drug of choice for the treatment and control of schistosomiasis [1–4] and the major- ity of the food-borne trematode infections [5,6]. PZQ has a good safety and therapeutic profile and has been widely used in community-based schistosomiasis control programmes. For example, in China and Egypt alone, more than 100 million doses have been administered over the past two decades [4,7]. The price of PZQ has plummeted since 1990 and a 2001 World Health Assembly resolution urges member states to regularly administer PZQ to school-aged children and other high-risk ∗ Corresponding author. Tel.: +44 207 594 3220; fax: +44 207 594 3226. E-mail address: elaine.holmes@imperial.ac.uk (E. Holmes). groups in areas that are highly endemic for schistosomiasis [1]. A global partnership has been created and the Schistosomiasis Control Initiative (SCI) is supporting several countries in sub- Saharan Africa with national control programmes emphasising PZQ-based chemotherapy [2,8]. These developments are welcomed but the price of PZQ still varies between schistosome-endemic countries and concern has been raised with regard to the PZQ content of tablets, lack of information on shelf life, and inter-manufacturer variation in physico-chemical properties and excipients [9]. Since the use of PZQ preparations with lower efficacy may contribute to the development of drug resistance, a ‘Concerted Action on Prazi- quantel’ initiative was launched in the late 1990s to collect and perform quantitative and qualitative analysis on PZQ from dif- ferent endemic settings and to monitor trends over time [9–11]. Findings reported at the 4th meeting of the ‘Concerted Action 0731-7085/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jpba.2007.06.017