J. Indian Chern. Soc., Vol. 84, January 2007, pp. 100-102 NOTE Application of ammonium metavanadate for the determination of some tubercular and adrenocortical steroid drugs I. C. Shukla*, P. K. Dwivedi, Santosh Kumar, B. K. Singh and Anurag Dubey Department of Chemistry, University of Allahabad, Allahabad-211 002, Uttar Pradesh, India E-mail : prof. icshukla@rediffmail. com Manuscript received 28 August 2006, accepted 30 October 2006 Abstract : A simple method has been developed for the determination of tubercular and adrenocortical steroid drugs e.g. isoniazid, ethambutol hydrochloride, rifampicin, pyrazinamide, cycloserine, betamethasune sodium phosphate, dexamethasone sodium phosphate, hydrocortisone sodium succinate and prednisolone sodium succinate in pure form and in their pharmaceutical preparations by ammonium metavanadate reagent in acidic medium. Keywords : Ammonium metavanadate, adrenocortical drugs. Tubercular and adrenocortical steroid drugs posses great medicinal value and a number of methods are available for their estimation 1 . In the present communication we report a simple method for the determination of these drugs, like isoniazid, ethambutol hydrochloride, rifampicin etc. Results and discussion The reaction conditions were established after studying the effect of variables such as reaction time, concentration and amount of reagent and sulphuric acid and reaction temperature. All the antitubercular drugs need 30 min and adrenocortical steroid drugs need 45 min to complete the reaction. The variation in the reaction time is due to difference in the structure of the compounds. The effect of concentration (0.01-0.5 N) of reagent (AMY) recommended that 0.3 N was suitable for accurate and concordant results. The presence of sulphuric acid was found to accelerate the reaction. The reactivity of the sample is very slow at ice cold temperature but increases with temperature (5-1 00 oq. Direct heating of the reaction mixture on flame or on sand bath was avoided because it gives inconsistent results. The stoichiometric ratio of the reagent with the sample has also been established for each compound. It varies with the structure of the compound. The present reagent works as a strong oxidizing agent and gives corresponding oxidized products consuming variable moles of the reagent. The determinations were done with varying sample sizes i.e. (1-10 mg) but for convenience results has been shown only with 3 mg sample size (Table 1). Recovery 100 Table 1. Determination of some antitubercular drugs in pure form and their pharmaceutical preparations with 0.3 N ammonium metavanadate reagent in acidic medium Sl. no. Drugs Molecu- larity Amount SD RSD obtained by (mg) (%) calculationa (mg) Antitubercular drugs (3 mg in 3.0 ml, reaction time 30 min) : I. Pyrazinamide (Pure) 6 a. P-zide (T) (Cadila Pharma) b. Pyzina (T) (Lupin Labs) 2. Isoniazid (Pure) a. Isokin (T) (Werner Lab) 6 6 4 4 b. Isonex (T) 4 (Ptizer Ltd.) 3. Ethambutol 8 hydrochloride (Pure) a. Combutal (T) 8 (Lupin Labs) b. Mycobutal (Cap) 8 (Cadila Pharma) 4. Rifampicin (Pure) 16 a. R-Cin (Cap) 16 (Lupin Labs) b. Zucox (Cap) 16 (Glaxo Ltd.) 2.9917 2.9935 2.9899 2.9912 2.9903 2.9909 2.9916 2.9927 2.9910 2.9915 2.9920 2.9850 0.0039 0.0046 0.0042 0.0045 0.0038 0.1304 0.1536 0.1405 0.1504 0.1270 0.0052 0.1738 0.0039 0.1303 0.0036 0.1203 0.0041 0.1370 0.0037 0.1237 0.0042 0.1404 0.0041 0.1373