Details

Autor(en) / Beteiligte

• Okamoto, Hirokazu
• Hashida, Mitsuru
• Sezaki, Hitoshi

Titel

Structure-activity relationship of 1-alkyl- or 1-alkenylazacycloalkanone derivatives as percutaneous penetration enhancers

Ist Teil von

• Journal of pharmaceutical sciences, 1988-05, Vol.77 (5), p.418-424

Ort / Verlag

Washington: Wiley Subscription Services, Inc., A Wiley Company

Erscheinungsjahr

1988

Quelle

Wiley-Blackwell Full Collection

Beschreibungen/Notizen

• Nine azacycloalkanone (5‐, 6‐, or 7‐member ring) derivatives with an alkyl or alkenyl (terpene) chain (10, 15, or 20 carbons) were compared with 1‐dodecylazacycloheptan‐2‐one (azone, 1) for their effects on the percutaneous penetration of 6‐mercaptopurine (6‐MP) through excised guinea pig skin. Pretreatment of skin with an enhancer markedly increased penetration and skin accumulation of 6‐MP. Superior enhancing effects were observed for enhancers having a terpene chain of 10 carbons and an azacyclo ring with one carbonyl group. Enhancers with a C20 tail chain were less effective. Enhancer ring size had little effect on enhancing activity, whereas the increase in the number of carbonyl groups in the ring caused a decrease. Computer fitting of a penetration profile to Fick's diffusion equation gave two parameters corresponding to diffusion and partitioning of 6‐MP. The diffusion parameter was little affected by pretreatment with an enhancer, whereas the partition parameter was markedly increased. This suggests that enhancement is determined by the ability to increase the drug partitioning into the skin and to enlarge the drug concentration gradient in the skin barrier. The primary skin irritation was examined with rabbit dorsal skin in vivo. The enhancers with an alkyl chain induced severer primary irritation (erythema and edema) than those with an alkenyl chain. From the balance between enhancing and irritating activities, it is concluded that 1‐geranylazacycloheptan‐2‐one (2), 1‐farnesylazacycloheptan‐2‐one (3), and 1‐farnesylazacyclopentan‐2‐one (10) are favorable enhancers.