ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 54, Number 5
JKCSEZ 54(5)
October 20, 2010 

The proposed method is simple, sensitive and specific Liquid chromatography-tandem mass spectrometry (LCESI- MS/MS) method for the quantification of Entacapone (EA) in human plasma using Entacapone-d10 (EAD10) as an internal standard (IS). Chromatographic separation was performed on Zorbax SB-C18, 2.1 × 50 mm, 5 μm column, mobile phase composed of 10 mM Ammonium formate (pH 3.0): Acetonitrile (60:40 v/v), with a flow-rate of 0.7 mL/min, followed by Liquid-liquid extraction. EA and EAD10 were detected with proton adducts at m/z 306.1 → 233.1 and 316.3 → 233.0 in multiple reaction monitoring (MRM) positive mode respectively. The method was validated over a linear concentration range of 1.00 - 2000.00 ng/mL with correlation coefficient (r²) ≥ 0.9993. Intra and inter-day Precision within 3.60 to 7.30 and 4.20 to 5.50% and Accuracy within 97.30 to 104.20 and 98.30 to 105.80% proved for EA. This method is successfully applied in the bioequivalence study of healthy Indian human volunteers.