title: The antinociceptive and anti-inflammatory effects of five depot formulations of ketorolac propyl ester in rats.
abstract: BACKGROUND
  Ketorolac is a potent nonsteroidal anti-inflammatory drug. Recently, a ketorolac prodrug, ketorolac propyl ester, was synthesized in our laboratory. The aim of the study was to evaluate the antinociceptive and anti-inflammatory effects of ketorolac propyl ester in five depot formulations. The vehicles used in these formulations were injectable vegetable oils, i.e., sesame oil, peanut oil, soybean oil, castor oil, and cottonseed oil. The traditional therapentic form of ketorolac tromethamine in saline was used as control.
  
  
  METHODS
  Six studies were carried out to test the antinociceptive and anti-inflammatory effects of intramuscular ketorolac tromethamine (in saline) and its propyl ester (in five depot formulations) 240 micromol/kg on Sprague-Dawley rats treated with intraplantar carrageenin.
  
  
  RESULTS
  Ketorolac tromethamine (in saline) produced an 8 h duration of action on both antinociception and anti-inflammation, whereas ketorolac propyl ester in five oily vehicles produced 54- to 78-h durations of actions in both antinociception and anti-inflammation. Ketorolac propyl ester in cottonseed oil produced a duration of action of 78h in both antinociception and anti-inflammation.
  
  
  CONCLUSIONS
  All five depot formulations of ketorolac propyl ester produced longer durations of antinociceptive and anti-inflammatory effects.
authors.affiliation: Departments of Anesthesiology and Medical Research, Chi-Mei Medical Center, Yung-Kang and Liou-Ying, Taiwan, ROC.
authors.forename: Li-Kai
authors.initials: LK
authors.lastname: Wang
authors.forename: Pei-Jung
authors.initials: PJ
authors.lastname: Wang
authors.forename: Chia-Hui
authors.initials: CH
authors.lastname: Hou
authors.forename: Chin-Chen
authors.initials: CC
authors.lastname: Chu
authors.forename: Jann-Inn
authors.initials: JI
authors.lastname: Tzeng
authors.forename: Ja-Ping
authors.initials: JP
authors.lastname: Shieh
authors.forename: Jhi-Joung
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002626:Chemistry, Pharmaceutical; D020910:Ketorolac / Q000494:pharmacology*; D020911:Ketorolac Tromethamine / Q000494:pharmacology*; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage; D011355:Prodrugs / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D010938:Plant Oils; D011355:Prodrugs; D020911:Ketorolac Tromethamine; D020910:Ketorolac