210DETERMINATION OF PIOGLITAZONE ENANTIOMERS IN TABLET BY LC-MS/MS METHODA simple, fast, specific and precise LC-MS/MS method was developed and validated for determination of pioglitazone enantiomers in pharmaceutical formulation. The interface used was Atmospheric Pressure Chemical Ionisation Technique. Analysis was performed using a ACI cellu 1 column (150 x 4.6 mm I.D., particle size 5 μ) by isocratic elution with 10 mM ammonium acetate: Acetonitrile (5:95) and flow rate was 0.5 mL/min. The calibration plot was linear over the range of 50 - 110 ng/mL of R-Pioglitazone and 40 - 100 ng/mL of S-Pioglitazone with a correlation of 0.999 for R and S Pioglitazone. The method was also validated for the precision and recovery. This optimized mobile phase separated R-Pioglitazone at 1.28 min and S-Pioglitazone at 2.58 min respectively. The proposed LC-MS/MS method was validated with respect to linearity, precision, accuracy, ruggedness and specificity. Vice chancellor, JSS University, Mysore, Karnataka, India.Research422013Pioglitazone, LC-MS/MS,Atmospheric Pressure Chemical Ionisation,Enantiomers,EnantiomersB. Gowramma,S. N. Meyyanathan,B. Babu,N. Krishnaveni,B. SureshDepartment of Pharmaceutical Chemistry JSS College of Pharmacy, (Off Campus-JSS University, Mysore) Rocklands, Udhagamandalam Tamilnadu – 643 001, India.,S. N. Meyyanathan JSS College of Pharmacy, (Off Campus-JSS University, Mysore) Rocklands, Udhagamandalam Tamilnadu – 643 001, India,S. N. Meyyanathan JSS College of Pharmacy, (Off Campus-JSS University, Mysore) Rocklands, Udhagamandalam Tamilnadu – 643 001, India,S. N. Meyyanathan JSS College of Pharmacy, (Off Campus-JSS University, Mysore) Rocklands, Udhagamandalam Tamilnadu – 643 001, India, Vice chancellor, JSS University, Mysore, Karnataka, India.