Study on the Pharmacokinetics of Ranolazine and Its Optical Isomer

OBJECTIVE To study the pharmacokinetics of ranolazine and its optical isomers in rat plasma. METHODS The concentrations of ranolazine in rats plasma at different time were determined by HPLC and the pharmacokinetic parameters were calculated. RESULTS The pharmacokinetic parmeters were as follows: the group of ranolazine: C_max (3.404±0.442), (5.858±0.422) and (8.186±0.625)mg·L^-1; T_max (0.250±0.000), (0.250±0.000) and (0.500±0.000)h; AUC_{0-12 h} (7.033±0.757), (13.055±1.665) and (20.899±2.965)mg·h·L^-1; T_1/2 (4.882±2.017), (6.757±2.932) and (4.603±0.462)h; the group of R-ranolazine: C_max (1.144±0.193), (3.999±0.830) and (5.987±0.321)mg·L^-1; T_max (0.500±0.000), (0.583±0.144) and (0.477±0.632)h; AUC_{0-12 h} (4.182±0.555), (8.831±1.092) and (13.517±7.238)mg·h·L^-1; T_1/2 (4.420±0.694), (3.430±0.773) and (4.221±2.881)h, the group of S-ranolazine C_max (0.756±0.227), (2.786±0.269) and (4.769±0.501)mg·L^-1; T_max (0.583±0.144), (0.500±0.000) and (0.417±0.144)h; AUC_{0-12 h} (3.696±0.821), (6.695±0.888) and (9.976±0.314)mg·h·L^-1; T_1/2 (3.191±0.322), (5.630±1.086) and (4.603±0.462)h. CONCLUSION Statistical results show that the value of C_max, T_max, T_1/2 and AUC of R-Ranolazine and S-Ranolazine has no significant difference. Ranolazine compared with different optical isomer has good absorption in the body.