DETERMINATION OF RO-48-3656 IN RAT PLASMA BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - COMPARISON OF 1.5-MU-M NONPOROUS SILICA TO 3.5-MU-M POROUS SILICA ANALYTICAL COLUMNS

We describe a method for measuring Ro 48-3656 in EDTA rat plasma by ne utral pH, reversed-phase high-performance liquid chromatography using a 1.5-mu m nonporous silica, C-18 analytical column and UV absorbance detection to support pharmacokinetic studies. We also describe a compa rison of the 1.5-mu m nonporous silica C-18 column versus 3.5-mu m por ous silica C-18 columns. The final method using the 1.5-mu m nonporous silica column demonstrated good precision (of both quantification and retention time), accuracy and recovery, linearity of dilution and lim it of quantification (40 ng/ml Ro 48-3656 using a 20 mu l injection). Samples of neat EDTA rat plasma were prepared by ultrafiltration follo wed by direct injection onto the HPLC column. (C) 1997 Elsevier Scienc e B.V.