title: Tissues distribution of R-(-)- and S-(+)-m-nisoldipine after single enantiomer administration in rats.
abstract: Rapid, sensitive, and selective high-performance liquid chromatography methods were developed and validated for determination of m-nisoldipine enantiomers in rat tissues. All of the samples were prepared based on a simple and efficient liquid-liquid extraction method. After validating that no racemation occurred by ULTRON ES-OVM (Japan), m-nisoldipine enantiomers were determined, respectively, on a reverse-phase C(18) column (5 microm, 250 x 4.6 mm). This method was applied to study tissue distribution of m-nisoldipine enantiomers in rats after a single administration of m-nisoldipine enantiomers. By the two-sample t test, there were basically no significant differences between the two enantiomers in each tissue ( p > .05), which indicates that they may have the same potency in rats. In small intestine, lung, liver, and spleen, the concentrations of R-(-)- and S-(+)-m-nisoldipine were high at 30 and 150 min than that at 90 min, which showed that m-nisoldipine enantiomers may have the phenomenon of hepatoenteral circulation. A small quantity of the prototype of R-(-)- and S-(+)-m-nisoldipine in brain showed that they can cross the blood-brain barrier to arrive at the brain tissue. The high quantity of distribution in lung and brain implied that the lipophilicity of the drug was powerful.
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, P.R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Qiao
authors.initials: Q
authors.lastname: Wang
authors.forename: Chunying
authors.initials: C
authors.lastname: Wang
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Jing
authors.forename: Kunfeng
authors.initials: K
authors.lastname: Duan
authors.forename: Xiang'ai
authors.initials: X
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.forename: Yaping
authors.initials: Y
authors.lastname: Tian
authors.forename: Lantong
authors.initials: L
authors.lastname: Zhang
authors.forename: Yumin
authors.initials: Y
authors.lastname: Du
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaona
authors.initials: X
authors.lastname: Sheng
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008297:Male; D015737:Nisoldipine / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D014018:Tissue Distribution
chemical_list: D002121:Calcium Channel Blockers; D015737:Nisoldipine