Self-emulsifying drug delivery systems (SEDDS) of coenzyme Q(10): formulation development and bioavailability assessment

The goals of our investigations are to develop and characterize self-emulsi fying drug delivery systems (SEDDS) of coenzyme Q(10) (CoQ(10)), using poly glycolyzed glycerides (PGG) as emulsifiers and to evaluate their bioavailab ility in dogs. Solubility of CoQ(10) was determined in various oils and sur factants. SEDDS consisted of oil, a surfactant and a cosurfactant. Four typ es of self-emulsifying formulations were prepared using two oils (Myvacet 9 -45 and Captex-200), two emulsifiers (Labrafac CM-10 and Labrasol) and a co surfactant (lauroglycol). In all the formulations, the level of CoQ(10) was fixed at 5.66% w/w of the vehicle. The in vitro self-emulsification proper ties and droplet size analysis of these formulations upon their addition to water under mild agitation conditions were studied. Pseudo-ternary phase d iagrams were constructed identifying the efficient self-emulsification regi on. From these studies, an optimized formulation was selected and its bioav ailability was compared with a powder formulation in dogs. Medium chain oil s and Myvacet 9-45 provided higher solubility than long chain oils. Efficie nt and better self-emulsification processes were observed for the systems c ontaining Labrafac CM-10 than formulations containing Labrasol. Addition of a cosurfactant improved the spontaneity of self-emulsification. From these studies, an optimized formulation consisting of Myvacet 9-45 (40%), Labras ol (50%) and lauroglycol (10%) was selected for its bioavailability assessm ent. A two-fold increase in the bioavailability was observed for the self-e mulsifying system compared to a powder formulation. SEDDS have improved the bioavailability of CoQ(10) significantly. The data suggest the potential u se of SEDDS to provide an efficient way of improving oral absorption of lip ophilic drugs. (C) 2001 Elsevier Science B.V. All rights reserved.