Oral delivery of capsaicin using MPEG-PCL nanoparticles

Acta Pharmacol Sin. 2015 Jan;36(1):139-48. doi: 10.1038/aps.2014.113. Epub 2014 Dec 1.


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(ε-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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Capsaicin / administration & dosage*
  • Capsaicin / chemistry*
  • Drug Carriers / administration & dosage
  • Drug Carriers / chemistry
  • Drug Delivery Systems / methods
  • Male
  • Nanoparticles / administration & dosage*
  • Nanoparticles / chemistry*
  • Polyesters / administration & dosage*
  • Polyesters / chemistry*
  • Polyethylene Glycols / administration & dosage*
  • Polyethylene Glycols / chemistry*
  • Rats
  • Rats, Sprague-Dawley


  • Drug Carriers
  • Polyesters
  • methoxy poly(ethylene glycol-co-epsilon-caprolactone)
  • Polyethylene Glycols
  • Capsaicin