[Assesement of tretinoin with a self-emulsifying formulation in vitro and in vivo].
OBJECTIVE
To evaluate the self-emulsifying ability and dissolution behavior of tretinoin in vitro and the pharmacokinetic behavior in beagle dogs.


METHODS
The self-emulsifying rate was evaluated by determining the intensity of scattered light at different time and the particle size of resultant emulsions after self-emulsifying were observed by optical microscope. The plasma concentrations were determined by HPLC and dissolution and pharmacokinetic behavior of self-emulsifying formulations were evaluated by comparison with commercial capsules.


RESULTS
The area under the curve (AUC) was significantly higher in the tretinoin self-emulsifying formulation group (3048.0 mg x h x L(-1)) than that in the commercial capsule group (1826.0 mg x h x L(-1)). Also, Tmax was smaller in the self-emulsifying formulation group (1.25 h) compared with market products (2 h) and the dissolved amount from self-emulsifying formulations in water at 15 min was much higher (more than 80%) than that of the market products (less than 5%).


CONCLUSIONS
The self-emulsifying drug delivery systems can increase drug dissolution in vitro and absorption in vivo significantly.
Quan
Dong-qin
DQ
Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing 100850, China. wzbqdq@sohu.com
Xu
Gui-xia
GX
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D004285:Dogs; D016503:Drug Delivery Systems; D045703:Emulsifying Agents; D004655:Emulsions; D008297:Male; D010316:Particle Size; D011136:Polysorbates; D012995:Solubility; D014212:Tretinoin / Q000008:administration & dosage* / Q000493:pharmacokinetics*
D045703:Emulsifying Agents; D004655:Emulsions; D011136:Polysorbates; D014212:Tretinoin