title: Potential of Piperazinylalkylester Prodrugs of 6-Methoxy-2-Naphthylacetic Acid (6-MNA) for Percutaneous Drug Delivery.
abstract: Piperazinylalkyl ester prodrugs (4a-5d) of 6-methoxy-2-naphthylacetic acid (6-MNA) (1) were synthesized and evaluated in vitro for the purpose of percutaneous drug delivery. These ionizable prodrugs exhibited varying aqueous solubilities and lipophilicities depending on the pH of the medium. The prodrugs (4a-5c) showed higher aqueous solubility and similar lipophilicity at pH 5.0 and lower aqueous solubility and higher lipophilicity at pH 7.4 in comparison to 6-MNA. The chemical and enzymatic hydrolyses of the prodrugs was investigated in aqueous buffer solutions (pH 5.0 and 7.4) and in 80% human serum (pH 7.4) at 37°C. The prodrugs showed moderate chemical stability (t 1/2 = 6-60 h) but got readily hydrolyzed enzymatically to 6-MNA with half-life ranging from 10-60 min. In the in vitro permeation study using rat skin, the flux of 6-MNA and the prodrugs was determined in aqueous buffers of pH 5.0 and 7.4. The prodrug (5b) showed 7.9- and 11.2-fold enhancement in skin permeation compared to 6-MNA (1) at pH 5.0 and 7.4, respectively. It was concluded that the parent NSAIDs having favorable pharmacokinetic and pharmacodynamic properties coupled with increased skin permeability of their prodrugs could give better options for the treatment of rheumatic diseases.
authors.affiliation: Pharmacy Department, Faculty of Technology & Engineering, The M.S. University of Baroda, Vadodara, 390001, India.
authors.forename: Vijay
authors.initials: V
authors.lastname: Pawar
authors.forename: Rushabh
authors.initials: R
authors.lastname: Thosani
authors.forename: Ashish
authors.initials: A
authors.lastname: Kanhed
authors.forename: Rajani
authors.initials: R
authors.lastname: Giridhar
authors.forename: Mange Ram
authors.initials: MR
authors.lastname: Yadav
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D016503:Drug Delivery Systems / Q000379:methods; D004952:Esters / Q000008:administration & dosage*; D006207:Half-Life; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008297:Male; D009280:Naphthaleneacetic Acids / Q000008:administration & dosage*; D010539:Permeability; D011355:Prodrugs / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D012995:Solubility
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004952:Esters; D009280:Naphthaleneacetic Acids; D011355:Prodrugs; C044612:6-methoxy-2-naphthylacetic acid