Determination of Finasteride by HPLC-MS and Study Its Pharmacokinetics

The study developed a sensitive and specific HPLC-MS method to determine finasteride levels in plasma and examined its pharmacokinetics in 18 healthy volunteers after administering a 5 mg oral dose. The method involved protein precipitation with acetonitrile and used a Nucleodur C18 column with a mobile phase of acetonitrile and ammonium acetate. The results showed a linear range of 1.53-306.70 ng/mL with high recovery rates and low variability. Key pharmacokinetic parameters included a t_max of 1.59 hours, C_max of 47.16 ng/mL, and AUC_0-24 of 319.29 ng·h/mL. The plasma concentration-time curve followed a two-compartment open model, with significant individual variability in pharmacokinetics.