Transdermal fentanyl matrix patches Matrifen and Durogesic DTrans are bioequivalent.

AIM

The pharmacokinetic profiles of the two commercially available transdermal fentanyl patches Matrifen (100 microg/h) and Durogesic DTrans (100 microg/h), used to manage severe chronic pain, were compared regarding their systemic exposure, rate of absorption, and safety.

METHODS

Transdermal matrix fentanyl patches [Matrifen or Durogesic DTrans (100 microg/h)] were applied for 72 h to 30 healthy male subjects in a randomized, four-period (two replicated treatment sequences), crossover study; 28 subjects completed the study. The pharmacokinetic parameters of fentanyl were determined for 144 h after application using plasma samples. Safety of the patches (adverse events) and performance (adhesion, skin irritation, residual fentanyl content in the patch) were evaluated.

RESULTS

The plasma concentration-time curves of Matrifen (Test) and Durogesic DTrans (Reference) were similar. The geometric least square means of the Test/Reference ratio (90% confidence intervals [CI]) were within the range of 80-125%, demonstrating bioequivalence of Matrifen and Durogesic DTrans: AUC(0-tlast) 92.5 (CI 88.7-96.4), AUC(0-inf) 91.7 (CI 88.0-95.7), and C(max) 98.3 (CI 92.9-104.1). After 72 h application, Matrifen had a more efficient utilization of fentanyl (mean+/-SD 82.3+/-9.43%) than Durogesic DTrans (52.3+/-12.8%), with substantially lower residual fentanyl in patch after use. The pharmacokinetic parameters showed lower intra- and inter-subject variability for Matrifen than for Durogesic DTrans patch.

CONCLUSIONS

Despite different technologies, the transdermal fentanyl patches Matrifen and Durogesic DTrans are bioequivalent. Compared with Durogesic DTrans, the Matrifen patch had lower initial and lower residual fentanyl content, as well as lower intra- and inter-subject variability, allowing reproducible drug delivery and reliable analgesia.