Lansoprazole For Injection Of Freeze-dried Liposomes

Lansoprazole is a new type of proton pump inhibitor (PPI) after omeprazole ,it has the curative effect on the peptic ulcer, it can be widely used in the digestive function disorder diseases relevant to acid secretory.The validated HPLC analytical method for Lansoprazole proliposome was developed. The solubilities of Lansoprazole in water, ethanol, methanol, chloroform,acetone,aceticether,especially in different pH were determined. Apparent partition coefficients in n-octyl alcohol:water and stability in different pH were also determined at ambient temperature by HPLC. The HPLC method for the content of Lansoprazole in proliposomes was established. The entrapment efficiency of Lansoprazole proliposome was determined by superfiltrate-HPLC method.The Lansoprazole liposome was prepared by ethanol injection- filtrate method. The four main factors such as the kind and the concentration of PC ,the ratio of PC to cholesterol and the ratio of PC to drug were studied. And the orthogonal design was adopted to obtain the optimized prescription, the main index was entrapment efficiency.The main process parameters including temperature,stirring rate and time ,injecting rate were also investigated according to stability of liposome.The freeze-dried process was as followed: pre-freeze for 8 hours under -47°C at fast rate,the drug was dried for 38 hours in vacuum degree<10Pa.The best cryoprotectant was also choosed,PC: sucrose:mannitol was l:1.5:1.5.The freeze-dried process was no effect on the release of Lansoprazole proliposome in vitro.The physicochemical properties of Lansoprazole proliposome were studied. The Lansoprazole proliposome was white,good and smooth, the mean number diameter was 158 nm, the mean volume diameter was 167 nm, the mean surface area diameter was 164 nm, pH value was 10.14, the Zeta potential was -32.2mV, the entrapment efficiency was 82.10%.The stability of Lansoprazole proliposome was reviewed with the index of physical stability factor like appearance, drug content, POV, pH value and chemical stability factor like entrapment efficiency ,morphology and reconstitution. The results of stability tests including effect fator test,accelerated test and long term test indicated that Lansoprazole proliposome should be preserved from light and stored at low temperature. The security investigation indicated that Lansoprazole proliposome preparation was non-irritant, pyrogen-free and non-hematolytic, the preparation met the regulations of the IV.