Objective: To study the pharmacokinetics and relative bioavailability of neostigmine bromide conventional tablets and sustained-release tablets in rabbits.
Methods: Six healthy rabbits were randomly divided into two groups for a cross self-contrast trial. RP-HPLC was used to detect plasma concentrations of neostigmine bromide. The pharmacokinetic parameters were calculated with the aid of DAS 2.0 software.
Results: The main pharmacokinetics parameters of the sustained-release tablets and conventional tablets were as follows, respectively: T(max)(3.67 +/- 1.51) hand (1.58 +/- 0.38) h; C(max) (5.04 +/- 1.19) mg/L and (4.56 +/- 1.70) mg/L; AUC(0 --> infinity) (32.82 +/- 9.88) mg/L x h and (29.84 +/- 14.27) mg/L x h. The relative bioavailability of the neostigmine bromide sustained-release tablets was 115.4%.
Conclusion: The pharmacokinetics of neostigmine bromide accords with two compartments model, showing constant plasma concentration and relatively high bioavailability.