To increase the aqueous solubility and poor bioavailability of capsaicin (CAS 404-86-4),
in this paper, the effects of hydroxypropyl-β-cyclodextrin (HP-β-CD) on the aqueous
solubility and the pharmacokinetic characteristics of capsaicin were investigated.
The corresponding inclusion complex of capsaicin/HP-β-CD at the molar ratio of 1:1
was obtained by the method of saturated aqueous solution and characterized by differential
scanning calorimetry and X-ray diffractometry. The dissolution rate of capsaicin was
significantly increased by the complexation with HP-β-CD, due to its solubilizing
activity. The absorption behavior and bioavailability of capsaicin and its complexation
were evaluated after their subcutaneous (s. c.) injection in rats. The absorption
rates of capsaicin across subcutaneous tissues and its bioavailability were significantly
enhanced by the formation of an inclusion complex with HP-β-CD. The present results
indicate the potential of utilizing HP-β-CD to improve the subcutaneous absorption
and bioavailability of capsaicin.
Key words
Capsaicin, bioavailability, inclusion complex, pharmacokinetics, subcutaneous absorption
- CAS 404-86-4 - Hydroxypropyl-β-cyclodextrin