In vitro Dissolution and Pharmacokinetics in Beagle Dogs of a Self-Emulsifying Formulation of Tretinoin

Aim In vitro dissolution test and pharmacokinetics in beagle dogs were conducted to assess the formulation of tretinoin in self-emulsifying systems. Methods The concentrations of tretinoin were determined by HPLC. A crossover study was performed in four fasting beagle dogs with the formulation of self-emulsifying systems and commercial capsules. Results The results showed that the dissolution rate in 15 min of tretinoin in self-emulsifying systems was higher than 80% while that of the commercial capsules was lower than 5%. The area under the plasma concentration-time curve (AUC) of the self-emulsifying formulation was significantly higher and C_ max was approximately two times greater than those of commercial capsule, respectively. In addition, the time taken to reach peak was shorter (2 h to 1.25 h) for self-emulsifying formulation of tretinoin. Conclusion The self-emulsifying drug delivery systems can significantly increase tretinoin in vitro dissolution and in vivo absorption.