title: Evaluation of an improved sustained-release buprenorphine formulation for use in mice.
abstract: OBJECTIVE
  To evaluate analgesic effects of an improved sustained-release buprenorphine (BUP-SR) formulation administered to mice.
  
  
  METHODS
  36 male Swiss-Webster mice.
  
  
  METHODS
  Mice were assigned to each of 3 treatment groups (n = 12 mice/group). Treatments were administered SC (vehicle [control treatment], 1.5 mg of buprenorphine hydrochloride [BUP-HCl]/kg, and 1.5 mg of BUP-SR/kg). Mice were evaluated (total activity, gastrointestinal tract motility, respiratory rate, cataleptic behavior, and tall-flick and hot plate nociception tests) to determine behavioral and physiologic responses at 4, 24, and 48 hours after treatment administration. Body weight and respiratory rate were measured before and at each time point after treatment administration.
  
  
  RESULTS
  SC administration of BUP-SR resulted in significant antinociception effects for 48 hours for the hot plate and tall-flick nociception tests without substantial adverse effects. Gastrointestinal tract motility and total activity were higher at 4 hours for mice receiving BUP-SR than for mice receiving the vehicle, but values were the same between these groups at 24 and 48 hours. The BUP-SR group had a lower respiratory rate than did the control group at all times after treatment administration. Mice treated with BUP-SR had no significant changes in body weight during the study, whereas mice treated with BUP-HCl had a significant decrease in body weight at 24 and 48 hours.
  
  
  CONCLUSIONS
  BUP-SR administration resulted in antinociception effects for 48 hours. Results of this study indicated that the improved BUP-SR formulation could be safely administered SC and conferred superior analgesia, compared with that for BUP-HCl, in mice.
authors: Department of Basic Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV 26506.
authors: Jason R
authors: JR
authors: Healy
authors: Jennifer L
authors: JL
authors: Tonkin
authors: Stacey R
authors: SR
authors: Kamarec
authors: Mitchell A
authors: MA
authors: Saludes
authors: Sherif Y
authors: SY
authors: Ibrahim
authors: Rae R
authors: RR
authors: Matsumoto
authors: Jeffrey H
authors: JH
authors: Wimsatt
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology*; D000818:Animals; D002047:Buprenorphine / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology*; D003692:Delayed-Action Preparations; D008297:Male; D051379:Mice; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D011897:Random Allocation
chemical_list: D000701:Analgesics, Opioid; D003692:Delayed-Action Preparations; D002047:Buprenorphine