Investigating the activity of 2-substituted alkyl-6-(2,5-dioxopyrrolidin-1-yl)hexanoates as skin penetration enhancers.
Skin penetration enhancers are used in the formulation of transdermal delivery systems for drugs that are otherwise not sufficiently skin-permeable. We generated two series of esters by multi-step synthesis with substituted 6-aminohexanoic acid as potential transdermal penetration enhancers by multi-step synthesis. The synthesis of all newly prepared compounds is presented here. Structure confirmation of all generated compounds was accomplished by (1)H NMR, (13)C NMR, IR and MS spectroscopy. All the prepared compounds were analyzed using RP-HPLC and their lipophilicity (logk) was determined. The hydrophobicity (logP/ClogP) of the studied compounds was also calculated using two commercially available programs and 3D structures of the selected compounds were investigated by means of ab initio calculations of geometry and molecular dynamic simulations. All the synthesized esters were tested for their in vitro transdermal penetration-enhancing activity and showed higher enhancement ratios than oleic acid. The highest enhancement ratios were exhibited by compound 5f (C((2)) substituted with piperidine-2-one, C(11) ester chain) and 5a (C((2)) substituted with piperidine-2-one, C(6) ester chain). The series with a ω-lactam ring (piperidin-2-one; 5a-g), showed slightly higher activities than those with morpholine (6a-6g). All of the agents showed minimal anti-proliferative activity (IC(50) >6.25μM), indicating they would have low cytotoxicity when administered as chemical penetration enhancers. The relationships between the lipophilicity and the chemical structure of the studied compounds, as well as the correlation between their chemical structure and transdermal penetration-enhancing activity, are discussed.
Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1/3, 612 42 Brno, Czech Republic.
Katerina
K
Brychtova
Radka
R
Opatrilova
Ivan
I
Raich
Danuta S
DS
Kalinowski
Lenka
L
Dvorakova
Lukas
L
Placek
Jozef
J
Csollei
Des R
DR
Richardson
Josef
J
Jampilek
D000279:Administration, Cutaneous; D002208:Caproates / Q000737:chemistry / Q000494:pharmacology*; D004337:Drug Carriers / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D012869:Skin Absorption / Q000187:drug effects*; D013329:Structure-Activity Relationship
D002208:Caproates; D004337:Drug Carriers