ABSTRACT
AIM To prepare capsaicin phospholipid complex gel and to investigate its pharmacokinetic behaviors.METHODS Phospholipid complex was prepared by solvent evaporation method,whose PBS solution was then poured into Carbopol 940 solution to prepare gel.With feed ratio (phospholipid-capsaicin),capsaicin concentration and reaction time as influencing factors,phospholipid complex's recombination rate as an evaluation index,the preparation was optimized by central composite design-response surface method on the basis of single factor experiment.Rabbits were percutaneously administered with phospholipid complex gel and ordinary gel,respectively,after which LC-MS/MS was adopted in the content determination of capsaicin in plasma.Then the drug concentration-time curves for two gels were drawn,followed by the calculation of their pharmacokinetic parameters.RESULTS The optimal conditions were determined to be 2.3:1 for feed ratio,16 mg/mL for capsaicin concentration,2 h for reaction time,and 55 ℃ for reaction temperature,the recombination rate was 97.84％.The phospholipid complex gel demonstrated its superiority to the ordinary gel with higher Cmax,AUC0→∞,and lower tmax.CONCLUSION Capsaicin prepared into phospholipid complex gel has obviously increased bioavailability and improved percutaneous absorption.