J. Indian Chern. Soc., NOTE Vol. 81, January 2004, pp. 84-86 Simultaneous determination of Glipizide and Metformin hydrochloride in pharmaceutical preparation by HPLC Anurag Dubey and I. C. Shukla* Department of Chemistry, University of Allahabad, Allahabad-211 002, India Manuscript received 10 October 2002, revised 4 June 2003, accepted 4 July 2003 A ne"' HPLC method for the determination of Glipizide and Metformin hydrochloride in combination has been described. The method is based on reverse phase liquid chromatography using C-18 column and a suitable moblie phase. The detection is done at 225 nm. The flow rate is adjusted at 1.0 ml!min and linearity is established. Glipizide 1 is l-cyclohexyl-3 { 4-[2-(5-methylpyrazine-2- carboxamido)ethyl]benzenesulfonyl} urea and Metformin hydrochloride 2 is I, !-dimethyl biguanide hydrochloride. Metformin hydrochloride is antihyperglycernic but not hypoglycernic 3 where as Glipizide is hypoglycemic. Metformin hydrochloride is often given in combination with sulfonyl ureas 4 . Literature survey reveals that some rnethodsl.2· 5 - 9 have been reported for the determination of Glipizide and Metforrnin hydrochloride individually. The present method describes simultaneous determination of two drugs in a single pharmaceutical prepamtion. Results and discussion Precision of the method was proved by observing the low value of RSD (o/o) in the present analytes (Table I). Table 1. Simultaneous assay ofGiipitide and Mcttormm hydrochlo- ride Label clain : Each uncoated tablet contains; Glipizidc : 5.00 mg. Mctf01min hydrochlunde: 500.00 mg Ex pt. Ghpitide Metformm hydrochlondc no. Assay Error RSD* Assay Error RSD' '7o % % % % 'Yr I. 100.15 +0.15 0.789 99.92 -0.08 0.615 2. 99.30 +0.70 0.602 I 00.02 +0.02 0.315 3. 99.90 -0.10 0.512 100.60 +0.60 0.492 4. I 00.32 + 0.32 0.612 99.30 -0.70 0.519 5. 100.71 +0.71 0.391 100.09 +0.09 0.312 *Each value is average of five determmations. Accuracy of the method was checked by recovery studies. Placebo was spiked with known quantities of standard drug at the level of 80% to 120% of label claim (Table 2). Linearity of the method was established by analysis of standard solution containing 1-3 )lg rnl- 1 and 100-300 )lg ml- 1 for Glipizide and Metforrnin hydrochloride respec- tively. The calibration curve drawn by plotting the peak area 84 Table 2. Recovery studies Sl. Glipizide Metform1n hydrochloride no. Amount Amount Recovel)'* Amount Amount Recovery* added found % added found % mg mg mg mg l. 4.00 4.01 100.25 400.00 401.20 100.30 2. 5.00 5.03 100.60 500.00 500 50 I00.10 6.00 5.98 99.66 600.00 599.39 99.89 ''Each value IS average of five determinalionb. versus concentration gaye correlation coefficient 0.9992 and 0.9996, slope 3798 and 281199 and intercept 50055 and 560055 for Glipizide and Metfromin hydrochloride respec- tively. Specificity of method by injecting the placebo cif the tablet. No interference of the placebo was observed with the principal peaks, hence the method was found to be specific for these two drugs. Raggedness of the method was established by carrying out the same experiment on different days, getting the similar analytical data. Robustness of the method was determined by slight change in chromatographic condition, pH (buffer) and tern- perature. The detection response was found to be satisfac- tory for both the drugs at the optimum wavelength of 225 nm. The column efficiency cletennined from the analyte peaks was not less than I 000 theoretical plates. The tailing factor for the analyte peaks was not more than 4.0 and the relative standard deviation for replicate injection was not more then 1.0%. The above method was validated as per U.S.P. guideline 10 . The present method is fast, selective pre- cise and reproducible hence it can be used for routine qual- ity control analysis. Experimental Water (HPLC grade), methanol (HPLC grade), sodium hydroxide (G.R. grade), ammonium dihydrogen orthophos- phate (extra pure), pump (Waters 510), UY detector