Res. J . of .Aleppo Univ. Basic Science Series No. 69 2010 Received 14/2/2010 Accepted 25/3/2010 Capillary Gas-Liquid Chromatographic Determination of Tinidazole in Pharmaceutical Dosage Forms Safwan Ashour, Amir Alhaj Sakur*, Manar Kudemati** Dept. of Chemistry, Faculty of Sciences, University of Aleppo. *Dept. of Analytical and Food Chemistry, Faculty of Pharmacy, University of Aleppo ** Postgraduate student, M.Sc. Abstract Powder (from tablets), containing ~500 mg of tinidazole (TNZ), was dissolved in methanol, 0.5 mL of this solution was taken and treated with 0.5 mL of metronidazole benzoate (4.0 mg mL -1 ; internal standard) and diluted to 5 mL with methanol. The solution was analysed on a capillary glass column TRB-5 (30 m×0.25 mm, 0.25 μm) operated at 140°C for 1 min, with a rise of 15°C min -1 up to 225 °C (held for 2 min) and then increased to a final temperature of 240 o C, with N 2 as carrier gas (3 mL min -1 ) and FID. The injector port and detector temperatures were maintained at 250 °C. Results of assay and recovery studies were statistically evaluated for its accuracy and precision. The retention times were about 9.19 and 11.53 min for tinidazole and I.S., respectively. The calibration graph (peak area) was rectilinear from 12.3 to 960.0 g mL -1 of tinidazole. Correlation coefficients (R 2 ) of the regression equations were greater than 0.999 in all cases. No interference from any components of pharmaceutical dosage forms or degradation products was observed. Keywords: Tinidazole; capillary gas-liquid chromatography; pharmaceutical dosage forms. Introduction Tinidazole (Fig. 1) is (1-[2-ethylsulphonyl) ethyl]-2-methyl-5- nitro-1H-imidazole. It is a 5-nitroimidazole derivative used for the treatment of giardiasis and susceptible protozoal infections. It has also been used in regimens for the eradication of Helicobacter pylori in peptic ulcer disease [1,2]. N N S O O CH 3 NO 2 CH 3 Figure 1. Chemical structure of tinidazole.