Preparation Of Taxol Nanoparticals-in-Microsphere System

Three dosage forms including Taxol microspheres(TAX-MPs), Taxol nanoparticals(TAX-NPs) and Taxol nanoparticals-in-microsphere system(TAX-NiMS) were prepared in this study. The optimal prescription was selected by evaluating particle size,encapsulation efficiency and drug loading. The drug release behavior in vitro was evaluated, and then the decreasing degree of drug burst release of these three dosage forms was compared.TAX-MPs and TAX-NPs were prepared by emulsion solvent evaporation method with poly(lactic-co-glycolic acid)(PLGA) as carriers. The single factor test was used to optimize the formulation, and the release characteristics in vitro were evaluated. The accumulative drug release amount of TAX-MPs in 12 h was 22.46%, and complete release time was 14 days, while the accumulative drug release amount of TAX-NPs in 12 h was35.46%, and complete release time was 13 days. In summary, the drug burst release amount of TAX-MPs and TAX-NPs was small, and the time of drug release was long.To further decrease the burst release of the drug, TAX-NiMS were prepared.TAX-NPs were prepared by emulsion solvent evaporation method with PLGA as carriers,then TAX-NiMS were prepared cladding TAX-NPs with calcium alginate as carriers by emulsification/internal gelation. Single factor test was used to optimize the formulation of TAX-NiMS, which took the encapsulation efficiency, drug loading and particle size as evaluation parameters. TAX-NiMS external and internal morphology were observed by SEM and TEM, and particle sizes and the release characteristics in vitro were evaluated.The optimized formulation of TAX-NiMS was as follows: TAX was 20 g·L-1, PLGA was100 g·L-1, PVA was 10 g·L-1, O/W was 1︰10, ultrasonic power was 300 W, and Na ALG was 15 g·L-1, Span-80 was 10 g·L-1, Ca CO3 / NaALG was 1︰3 and W/O was 1︰5. The encapsulation yield, drug loading and mean particle size of TAX-NiMS prepared in these conditions were(84.33±1.11)%,(1.12±0.15)% and(2.678±0.416) μm respectively. The accumulative drug release amount in 12 h was 16.51%. The preparation method of TAX-NiMS is stable and reliable, and the burst release of TAX-NiMS is evidently decreased, which provides a new way to develop new dosage forms.