Comparative Pharmacokinetics Study of Four Commercial Formulations of Buprenorphine in Yorkshire swine (Sus scrofa domesticus). SM Ganesan, R Tzafriri, PA Lester, P Markham, M Williams-Fritze
Opioids are commonly utilized for controlling pain in humans and animals. Specifically, buprenorphine has been shown to provide excellent post-operative analgesia in laboratory species. However, limited pharmacokinetic data are available for commercially available buprenorphine formulations in swine. This study aimed to fill this gap by providing comparative pharmacokinetics data for commercially available buprenorphine formulations, including the transdermal buprenorphine. Here, we describe a crossover study where 4 different buprenorphine formulations were compared: regular buprenorphine (Bup), highly concentrated buprenorphine (Bup-HC), extended-release buprenorphine (Bup-SR) and transdermal buprenorphine (Bup-T) in 3 juvenile male Yorkshire swine. Therapeutic concentrations (≥0.01 ng/ml) of Bup, Bup-HC and Bup-SR formulations lasted in plasma for 4 , 8 and 96 hrs, respectively. Both low and high concentrations of transdermal buprenorphine (Bup-TL and Bup-TH) maintained therapeutic concentration until the final collection time (96 hrs). Bup-TL and Bup-TH resulted in a Cmax (ng/ml) of 53.0 and 139.54, compared with 3.48, 4.10, 3.67 for Bup, Bup-SR, and Bup HC, respectively. Therapeutic plasma buprenorphine concentration threshold was achieved within 60 minutes for all buprenorphine formulations tested in this study, thereby expanding our arsenal of drugs for pain management in laboratory swine. Additionally, no skin reactions were seen in association with any of these formulations, including Bup-SR. In summary, these data support the potential use of Bup-SR and Bup-T for continued post-operative analgesia with significant improvement in animal welfare in swine. Further studies should be performed to evaluate the clinical efficacy of long-acting buprenorphine formulations. To our knowledge, this is the first study to compare the pharmacokinetics of transdermal buprenorphine with other buprenorphine formulations in Yorkshire swine.