Oral delivery of capsaicin using MPEG-PC nanoparticles
摘要
Aim： To prepare a biodegradable polymeric carrier for oral delivery of a water-insoluble drug capsaicin （CAP） and evaluate its quality. Methods： CAP-loaded methoxy poly （ethylene glycol）-poly（c-caprolactone） nanoparticles （CAP/NPs） were prepared using a modified emulsification solvent diffusion technique. The quality of CAP/NPs were evaluated using transmission electron microscopy, powder X-ray diffraction, differential scanning calorimetry and Fourier transform infrared techniques. A dialysis method was used to analyze the in vitro release profile of CAP from the CAP/NPs. Adult male rats were orally administered CAP/NPs （35 mg/kg）; and the plasma concentrations of CAP were measured with a validated HPLC method. The morphology of rat gastric mucosa was studied with HE staining. Results： CAP/NPs had an average diameter of 82.54±0.51 nm, high drug-loading capacity of 14.0%±0.13% and high stability. CAP/NPs showed a biphasic release profile in vitro： the burst release was less than 25% of the loaded drug within 12 h followed by a more sustained release for 60 h. The pharmacokinetics study showed that the mean maximum plasma concentration was observed 4 h after oral administered of CAP/NPs, and approximately 90 ng/mL of CAP was detected in serum after 36 h. The area under the curve for the CAP/NPs group was approximately 6-fold higher than that for raw CAP suspension. Histological studies showed that CAP/NPs markedly reduced CAP-caused gastric mucosa irritation. Conclusion： CAP/NPs significantly enhance the bioavailability of CAP and markedly reduce gastric mucosa irritation in rats.