Preparation Of Two Anti-Cancer Drug Liposomes And Preliminary Cytology Investigation On Rhythmical Administration

Objective:To prepare long-circulating liposomes with two anti-tumor drugs, name of drug (DOX) and name of drug (5-FURP), and to investigate the inhibition ratios of the model drugs of different dosage forms with rhythmical low-dosage administration on human ovarian cancer HO8910 cells.Methods:Ammonium sulphate-gradient and pH-gradient assay were used to prepare DOX-PEG-L and reverse phase evaporation was used to prepare 5-FURP-PEG-L. Leakage rate, transmittance and phosphatide contents were applied to determine the stability of the liposomes after they were stored close tightly for one month at 4 and 25℃, respectively . MTT assay was applied to investigate the cytotoxicity of DOX-PEG-L,DOX,5-FURP-PEG-L and 5-FURP with common administration after 24h and rhythmical low-dosage administration after 144h on HO8910 cells.Results :The optimal prescription of DOX-PEG-L by orthogonal design test was: ratio of the drug to lipid (1:10), ratio of phosphatide to cholesterol (3:1), external water phase pH of 7.6, ammonium sulfate concentration of 155mmol/L, drug-loading temperature of 60℃, and the mean entrapment rate was 92.86%. The optimal prescription of 5-FURP -PEG-L was: ratio of the drug to lipid (1:10), ratio of phosphatide to cholesterol (3:1), the ultrasound time of 5min, and the mean entrapment rate was 94.35%. The particle diameters of the liposomes were well-distributed and the mean diameter was less than 200nm by Zetasizer Nanoparticle instrument/Zeta electronic potential detector. The cytotoxicity test showed that IC50 of DOX and DOX-PEG-L were 0.62μg/mL,0.46μg/mL respectively at 24h and 0.06μg/mL,0.01μg/mL at 144h; and that IC50 of 5-FURP and 5-FURP-PEG-L were 1.12μg/mL,0.97μg/mL respectively at 24h and 0.45μg/mL,0.06μg/mL at 144h.Conclusions:The methods of detecting the drug contents and the entrapment rate of DOX-PEG-L and 5-FURP-PEG-L using UV detection and separating the liposomes using Sephadex G-50 sephadex column were accurate, fast and convenient. The stability experiment showed that liposomes were relatively stable at the storage temperature of 4℃.The vitro drug-releasing experiment indicated that drugs after encapsulated exhibited better sustained-release efficacy. Cytology investigation indicated that the inhibition ratios of the two anti-tumor drugs with rhythmical low-dosage administration were much higher than MTD chemotherapy administration on HO8910 cells, and the inhibition ratios of the liposome drugs with rhythmical low-dosage administration were much higher than free drugs. The concentration of DOX-PEG-L with rhythmical low-dosage administration was 1/100 of that of MTD up to the same inhibition ratios on HO8910 cells, and the concentration of 5-FURP-PEG-L was 1/160 of that of MTD.