| The influence of chitosan on the degradation characteristics of paclitaxel-loaded Poly (Lactic-co-Glycolic Acid) (PLGA) rod-shaped implants was investigated and modeled. The implant was designed for sustained release of the hydrophobic chemotherapeutic paclitaxel (PTX) intramuscularly or subcutaneously. In this study, integration of PTX and PLGA was achieved via a solvent evaporation method resulting in a solid dispersion of the substances. To customize degradation of the implants and secure delivery of high doses of PTX, chitosan and the PLGA-PTX blend were mixed in a 30:70 mass ratio. Cryomilling was utilized to create the chitosan-PLGA-PTX mixture, due to its proven effectiveness in producing homogenous blends. Implants were then fabricated into rods by injection molding and characterized in terms of content uniformity, morphology, and thermal property. The integrity of the blends was ascertained via x-ray diffraction, while miscibility between the drug and excipients was established by differential scanning calorimetry. In vitro drug release was studied in a phosphate buffer of pH 7.4 and measured by ultraviolet-visible spectrophotometry (UV-Vis). Meanwhile, the degradation rate was determined by quantifying mass loss at various points in 30 days. This study revealed the chitosan blended PTX-loaded PLGA implant possesses a longer, yet steadier, sustained drug release behavior than the PTX-loaded PLGA implant. The results suggest that introducing chitosan into PLGA implants through this fabrication method could be integrated to regulate and control the degradation rate of PLGA implants. |
