Transdermal delivery of penetrants with differing lipophilicities using O-acylmenthol derivatives as penetration enhancers.
To develop more effective compounds as penetration enhancers, O-acylmenthol derivatives were synthesized by l-menthol and saturated fatty acid, O-ethylmenthol (MET), was also synthesized as a reference compound. Their promoting activity on the percutaneous absorption of five model drugs, 5-fluorouracil (5-FU), isosorbide dinitrate (ISDN), lidocaine (LD), ketoprofen (KP), indomethacin (IM), which were selected based on their lipophilicity represented by log KO/W, was tested in vitro across full thickness rat skin with each of the evaluated drugs in saturated donor solution. Only 2-isopropyl-5-methylcyclohexyl tetradecanoate (C14 alkyl chain) had promoting effects on the percutaneous permeation of 5-FU; 2-isopropyl-5-methylcyclohexyl hexanoate (C6 alkyl chain), which increased the permeation coefficient (P) 1.91-fold, had the highest permeation for ISDN; in the case of LD, the highest increase in P was observed with 2-isopropyl-5-methylcyclohexyl heptanoate (C7 alkyl chain), which increased the P by 1.58-fold; MET, which increased the P by 2.02-fold, provided the best enhancement for KP; 2-isopropyl-5-methylcyclohexyl heptanoate (C7 alkyl chain) produced the highest increase in P, 3.70-fold for IM. These results suggest that some newly designed percutaneous absorption enhancers have the potential to enhance drugs with different lipophilicities. A chain length of C6-C10 seemed to be favorable for lipophilic drugs, while C14 was the most effective enhancer for hydrophilic drug (5-FU).
Zhao
Ligang
L
Department of Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang, China.
Fang
Liang
L
Xu
Yongnan
Y
Liu
Shu
S
He
Zhonggui
Z
Zhao
Yanyan
Y
D000279:Administration, Cutaneous; D000818:Animals; D002626:Chemistry, Pharmaceutical / Q000379:methods; D005227:Fatty Acids / Q000737:chemistry; D005472:Fluorouracil / Q000008:administration & dosage; D007213:Indomethacin / Q000008:administration & dosage; D007548:Isosorbide Dinitrate / Q000008:administration & dosage; D007660:Ketoprofen / Q000008:administration & dosage; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008610:Menthol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D012869:Skin Absorption; D013678:Technology, Pharmaceutical / Q000379:methods
D005227:Fatty Acids; D008610:Menthol; D007660:Ketoprofen; D008012:Lidocaine; D007548:Isosorbide Dinitrate; D005472:Fluorouracil; D007213:Indomethacin