Preparation and delivery of morphine sustained-release liquid suppository

Objective: To prepare morphine sustained-release liquid suppositories with poloxamer 407, poloxamer 188, the bioadhesive polymer cabopol and the permeability enhancer azone, and to evaluate its characteristics between in vitro release and in vivo absorption. Methods: The physicochemical properties such as gelation temperature, gel strength, and bioadhesive force were determined. The release of morphine was measured with new scanning instrument made by our lab, and the drug absorption was performed in Beagle dogs. The 3p97 program was used to calculate the pharmacokinetic parameters of morphine. Results: Drug release pattern in vitro was demonstrated to fit zero-order kinetics, and in vivo profile of absorption was to fit one compartment model. The pharmacokinetics pharmerers were: t 1/2(Ke)=5.65 h, t 1/2(Ka)=0.78 h, C max=361.8 ng · mL -1, AUC 0~∞=4 046.1 ng · h · mL -1, and MRT=10.94 h. Conclusion: This preparation is characterized to be sustained releasing.