Study on pharmacokinetics and relative bioavailability of rapid oral disintegrating tablet of dimenhydrinate / 第二军医大学学报

ABSTRACT

Objective: To compare the pharmacokinetics and relative bioavailability of rapid oral disintegrating tablet of dimenhydrinate (RODTD) and those of market available tablet of dimenhydrinate (DMH). Methods: Eight healthy volunteers were evenly randomized into 2 groups, one group received RODTD (25 mg) and the other received available market tablet of dimenhydrinate (25 mg). The blood levels of DMH were determined by high performance liquid chromatography (HPLC) before and after drug administration in 2 groups. Chromatography conditions were Nova-Pak C18 as chromatographic column, methanol triethylamine buffer (1 1),flow rate 1.0 ml/min, detection wavelength 225 nm, and room temperature. The pharmacokinetics and relative bioavailability of RODTD and market available tablets were investigated. Results: The standard curve of DMH in the blank plasma was linear within the range of 5-500 ng/ml, with the regression equation being C=0.004 4 A+4.745 and R2=0.996. The limit of detection was 2 ng/ml; the average recovery rate was (90.55±4.69)% and the RSD was 0.041%. The intra-day derivations of 3 different concentrations (low, middle, and high) of plasma were 9.27%, 4.93%, and 2.95%, respectively (n=5), and the inter-day derivations were 9.97%, 3.81%, and 3.06%, respectively (n=5). Blood samples (3 ml) were subjected to HPLC assay and significant difference was found between the 2 forms of DMH. The pharmacokinetic parameters of RODTD were AUC=(602.04±113.82) ng • h • ml-1, Cmax=(95.86±21.28) ng • h • ml-1, and TPeak=(1.8±0.32) h; the pharmacokinetic parameters of market available tablets were AUC=(342.73±84.96) ng • h • ml-1 Cmax=(46.34± 10.32) ng • ml-1, and TPeak=(2.65±0.24) h. Statistical analysis showed there was significant difference in the relative bioavailability of 2 forms of DMH(P<0.01). The relative bioavailability of RODTD to market tablet was 175.66%. Conclusion: The developed RODTD can obviously increase the relative bioavailability of DMH.