Abstract: AIM: To study a method of HPLC determination of R-isomers ofPenehyclidine hydrochloride(RPHC)in mouse urine excretion.METHODS: Urine samples were collected andPrepared after i.m.a single dose 30μg of R-PHC in mice.The HPLC system consisted of Spherisorb SiO₂column,methanol-dichloromethaneammonialiquor(8∶2∶0.1)as mobilePhase with 254 nm,flow rate:0.8 ml·min^-1,and injection volume of 20μl.RESULTS: Thelinear range was 0.5 -100mg·L^-1(r =0.9994 and 0.9997,respectively),and the average recovery was more than 85 %.The RSD of intra-day and inter-day assays of two isomers were allless than 13 %.Thelimit of detectionProved to be 0.1μg·ml^-1.The ratio of R-1/R-2 in urine changed within the time after dosing.The cumulative excretion of the two optical isomers had distinguished differences(P<0.05)in urine.CONCLUSION: This HPLC method is simple and convenient,and able to investigate the stereo-selective excretion of R-PHC isomers in urine.

Key words: pharmacology, HPLC, penethyclidine hydrochloride, R-isomers, excretion