Preparation of harmine hydrochloride liposome by active loading method / 中草药

ABSTRACT

Objective To prepare a harmine hydrochloride liposome formulation with high encapsulation efficiency. Methods Preformulation investigation was carried out to obtain the drug physicochemical properties such as solubility and lgD in buffers of different pH value. Harmine hydrochloride was encapsulated into liposomes by active loading method. Encapsulation efficiency of liposomes was determined after the free drug was separated from liposome by ultrafiltration. The influence factors on the encapsulation efficiency including drug-lipid weight ratio, incubation temperature, pH value of external water phase were investigated. Results As the pH value increasing, the solubility of harmine hydrochloride was decreased, while the apparent oil-water distribution coefficient was increased. By active loading method, the encapsulation efficiency could be over 80% when the drug to lipid weight ratio was under 1∶5. The pH gradient between intervesicle and intravesicle obviously influenced the encapsulation efficiency, while incubation temperature had little effect on encapsulation efficiency. Conclusion Active loading is suitable for preparing harmine hydrochloride liposome with high encapsulation efficiency.