Stereoselective urinary excretion of S-(-)- and R-(+)-propranolol glucuronide following oral administration of RS-propranolol in Chinese Han subjects.
OBJECTIVE
To study the stereoselectivity of phase II glucuronidation metabolism of side-chain propranolol in Chinese Han population.


METHODS
Sixteen adult Chinese Han volunteers with an average age of 20 years were given a single oral dose of 20 mg racemic propranolol. Human urine at indicated time after administration was collected and S-(-)-propranolol glucuronide and R-(+)-propranolol glucuronide were determined simultaneously by using RP-HPLC.


RESULTS
The mean values of k were 0.19+/-0.04 h(-1) and 0.28+/-0.06 h(-1), of t(1/2) 3.56+/-0.73 h and 2.45+/-0.50 h, of T(max) 2.21+/-0.45 and 1.75+/-0.33 h, and of Xu(0-24) 5.65+/-0.98 and 2.95+/-0.62 micromoL for S-(-)- and R-(+)-propranolol glucuronide, respectively. The cumulative excretion percentages in urine of doses were 14.7+/-2.46% and 7.68+/-1.60% for S-(-)- and R-(+)-propranolol glucuronide, respectively. The results showed the elimination rate constant k of S-(-)-propranolol glucuronide was less than that of R-(+)-propranolol glucuronide; and the elimination half-life (t(1/2)), T(max) and the cumulative excretion amount(Xu(0-24)) of R-(+)-propranolol glucuronide were significantly less than that of S-(-)-propranolol glucuronide.


CONCLUSIONS
The propranolol glucuronidation of the side-chain undergoes stereoselective excretion in Chinese Han population after an oral administration of racemic propranolol.
Luan
Lian-Jun
LJ
Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310031, Zhejiang Province, China.
Shao
Qing
Q
Ma
Jian-Yin
JY
Zeng
Su
S
D000284:Administration, Oral; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000652:urine*; D000328:Adult; D044466:Asian People; D006801:Humans; D011433:Propranolol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics* / Q000652:urine*; D013237:Stereoisomerism
D000319:Adrenergic beta-Antagonists; C022056:propranolol glucuronide; D011433:Propranolol