ABSTRACT
OBJECTIVE： To prepare Capsaicin solid dispersion， to optimize its formulation and characterize the dispersion. METHODS： Capsaicin solid dispersion was prepared by melting method using P188 or PEG4000 as carrier. Using 60 min accumulative dissolution rate in vitro as index， orthogonal test was used to optimize type of carrier， drug ratio and stirring time. Validation test was conducted. The stability of Capsaicin solid dispersion within 0， 30， 180 d was investigated at 40 ℃ under the relative humidity of 75％， and X-ray diffraction （XRD） was used to analyze whether there were peaks. Capsaicin solid dispersion was characterized by differential scanning calorimetry （DSC） and XRD. RESULTS： The optimized formula included P188-PEG4000 as carrier， capsaicin-P188-PEG 4000 mass ratio of 1 ∶ 5 ∶ 3， stirring for 20 min. Accumulative dissolution rate in vitro of Capsaicin solid dispersion was 84.6％ within 60 min （n＝3）， and the preparation kept stable within 180 d [RSD of content was 3％ （n＝3）； XRD showed that there was no peak]. The phase characteristics showed that capsaicin was highly dispersed in the amorphous or molecular state in carrier. CONCLUSIONS： The optimized technology can be used to prepare Capsaicin solid dispersion， and improves more than 80％ dissolution rate in vitro at 60 min. It is stable， simple and feasible.
ABSTRACT
AIM: To study the pharmacokinetics of oleanolic acid liposomes in rats.METHODS: Oleanolic acid liposomes were prepared by ethanol injection-sonication;The pharmaceutical properties including morphology,encapsulation efficiency,particle size,zeta potential were determined.Rats were injected with oleanolic acid lipo-somes and oleanolic acid solution via the tail,respectively.The plasma concentrations of sample in rats were assayed by RP-HPLC.The pharmacokinetic parameters were computered by 3P97 program package.RESULTS: Oleanolic acid liposomes showed almost spherical,the mean diametre was(206.4 ? 4.7) nm.The encapsulation efficiency of oleanolic acid liposomes could be more than 90% based on orthogonal design,and no haemolyticus existed.The plasma concentration-time curves of the oleanolic acid liposomes conformed to a two-compartment model.T1/2? of oleanolic acid liposomes was(33.59 ? 12.53) min,AUC was(240.13 ? 23.62)(?g/mL.min),obviously higher than that of the control preparation.CONCLUSION: The oleanolic acid liposomes with high entrapment efficiency and even size has a good pharmacokinetic parameters by comparison with non-liposomes.