title: Comparison of the anti-inflammatory and analgesic effects in rats of diclofenac-sodium, felbinac and indomethacin patches.
abstract: BACKGROUND
  Topically applied nonsteroidal anti-inflammatory drugs (NSAIDs) are used widely for the treatment of pain and inflammation in musculoskeletal disorders. This study compared the analgesic and anti-inflammatory effects of patches of 1% diclofenac-sodium, 3.5% and 0.5% felbinac and 3.75% indomethacin in rats using the carrageenan-induced paw pad edema model and the brewer's yeast-induced hyper algesia model. Two studies were conducted: in the preliminary study, the patch was removed at 2 or 24 hrs after application, and in the main study the patch was removed at 2 hrs. The volume of the right hind paw and the pain threshold were assessed at 1, 3, 5, and 7 hrs after induction of inflammation in both studies.
  
  
  RESULTS
  In the main study, the edema ratio in the 1% diclofenac group at 5 hrs after induction of inflammation and the AUEC (Area Under the Effect Curve) were significantly lower than in the control animals (p=0.009). The edema suppression rate in the 1% diclofenac group (12.1-33.2%) was higher than in the 3.5% and 0.5% felbinac and 3.75% indomethacin groups. The pain threshold ratio did not decrease in the 1% diclofenac group and it was significantly higher than in the control group at 3 (p=0.0004) and 5 hrs (p=0.029). The 1/AUEC was significantly lower than that in the control group (p=0.004) and the lowest among all the NSAID groups.
  
  
  CONCLUSIONS
  This study demonstrated that the analgesic and anti-inflammatory effects of the 1% diclofenac sodium patch in a rat model may be exerted more promptly and persistently than with the 3.5% and 0.5% felbinac and 3.75% indomethacin patches.
authors.affiliation: Hoshi University, Japan;
authors.forename: Kozo
authors.initials: K
authors.lastname: Takayama
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hirose
authors.forename: Ikuko
authors.initials: I
authors.lastname: Suda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyazaki
authors.forename: Masao
authors.initials: M
authors.lastname: Oguchi
authors.forename: Masako
authors.initials: M
authors.lastname: Onotogi
authors.forename: Grigorios
authors.initials: G
authors.lastname: Fotopoulos
keywords: analgesic effect; anti-inflammatory effect; brewer’s yeast-induced hyper algesia; carrageenan-induced paw pad edema; diclofenac; felbinac; indomethacin; patch; topical nonsteroidal anti-inflammatory drugs