Study On The Hyaluronic Acid Modified Paclitaxel Loaded Liposomes

OBJECTIVE:To establish the assay method of liposomes loaded with Paclitaxel content in vitro and the assay method of encapsulation efficiency; Prepare paclitaxel-containing cationic liposomes and investigate the single factor to determine the optimal prescription; Prepare paclitaxe loaded liposomes that modified with hyaluronic acid. Observe and study is freeze-drying preparation, releasing in vitro, pharmacodynamics in vivo as well as its pharmacokinetics.METHODS:The method of HPLC to assay the paclitaxel loaded with liposomes and the encapsulation efficiency of liposomes in vitro were established. liposomes loaded with Paclitaxel-containing cationic was prepared by the film dispersion method and adopt the single factor investigation to investigate the factors that affect the forming of the liposomes to get the optimal prescription; The paclitaxel liposomes loaded positive electricity cationic surrounded by hyaluronic acid loaded with negative electricity, and its morpHology was observed by transmission electron microscope, its partical sizes was determined by laser particle analyzer, its zeta potential was determined by Potential analyzer; and after freeze-drying, its partical size,zeta potential,encapsulation efficiency and drug loading capacity were investigated, as well as its condition and the speed of redissolve after freeze-drying. the release of drug was studied in vitro by dynamic membrane dialysis; the pharmacodynamic and pharmacokinetic were evaluated in vivo with tumor-bearing mice.RESULTS:The assay methods of paclitaxel loaded by liposomes in-vitro and the encapsulation efficiency were established; liposomes loaded with paclitaxel were prepared, and the optimal prescription had been got by single factor investigation method; The partical size of the optimal prescription was (162.1±4.59)nm, zeta potential was (27.04±5.88) mV, encapsulation efficiency was (97.63±1.47)%,and drug loading capacity was(4.05±0.08)%;liposomes loaded paclitaxel and modified with hyaluronic acid were prepared, and its partical size is (237.87±6.63) nm, zeta potential is (-29.99±0.61)mV, encapsulation efficiency was (89.44±3.80)%,and drug loading capacity was (3.60±0.15)%; With the above results, liposome particle size increases slightly after the modification of hyaluronic acid, potential changed from positive to negative, and encapsulation efficiency and drug loading did not change significantly. In vitro release results, the fitting equation of taxol group was lnln(1/(1-Q/100))=0.96321nt-2.3540(r=0.9970), showed that; the drug release consistent with Weber equation to prove the drug release quickly. The fitting equation of preparation group is100-Q=45.9567e-0.2010t+54.8828e-0.0026t, proved the drug release slowly. The vivo pharmacodynamic tests proved that the Preparation inhibitory effect is obvious (P<0.001), there are significant differences compared HA-PCL group with taxol group. There was no significant difference in plasma concentration formulation group and taxol group on five minutes; Drug concentration formulations were significantly lower than taxol group (P<0.05) on60minutes and120minutes.CONCLUSION:The preparation of paclitaxel liposome modified with hyaluronic acid was simple; it has stable physical and chemical properties, and the inhibitory effect on tumor was obvious in vivo, and its sustained release effect was significant.