Synthesis and properties of a naproxen polymeric prodrug.
A water-soluble polymeric prodrug containing a naproxen moiety was synthesized. The carboxylic groups of naproxen were condensed with the hydroxyl groups of 2-hydroxyethyl methacrylate (HEMA) to produce a drug-linked monomer, denoted HN. The polymeric prodrug was prepared by copolymerization of HN with methacrylic acid. The molar percentage of HN in the polymeric prodrug was 26 mol%, as determined by 1H NMR. To investigate the pertinence of this polymeric prodrug, the hydrolysis was studied in-vitro with or without esterase or lipase. The kinetics of enzymatic catalysis was calculated from a Lineweaver-Burk plot. The anti-inflammatory activity was evaluated using the carrageenan-induced oedema test. The polymeric prodrug released a major fraction of the free naproxen and a significant fraction of the hydroxyethyl ester derived-naproxen. The maximum hydrolysis rate Vmax, and the Michaelis constant Km were calculated to be 2.16 x 10(-5) equiv. mol L-1 min-1 and 5.11 x 10(-2) equiv. mol L-1. The maximum anti-inflammatory inhibition of free naproxen appeared at 2 h and quickly decreased thereafter. In contrast, the polymeric prodrug showed a maximum at around 2-3 h and then slowly decreased. This indicates that the polymeric prodrug displays greater potency than free naproxen in the inhibition of acute inflammatory processes over long periods.
Wang
L F
LF
Kaohsiung Medical University, School of Chemistry, 100 Shih-Chun 1st Rd, Kaohsiung City 80708, Taiwan. lfwang@cc.kmu.edu.tw
Chiang
H N
HN
Chen
W B
WB
D000818:Animals; D002351:Carrageenan / Q000008:administration & dosage / Q000494:pharmacology; D002384:Catalysis; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy*; D004950:Esterases / Q000494:pharmacology; D005260:Female; D006868:Hydrolysis; D007700:Kinetics; D008049:Lipase / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D009288:Naproxen / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology*; D011108:Polymers; D011355:Prodrugs / Q000138:chemical synthesis / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D011108:Polymers; D011355:Prodrugs; D009288:Naproxen; D002351:Carrageenan; D004950:Esterases; D008049:Lipase