Ocular pharmacokinetics of dexamethasone cubosomes in rabbit aqueous humor / 中国药科大学学报

ABSTRACT

Aim: To prepare novel cubosome system for effective ocular drug delivery with dexamethasone(DEX) as model drug, and investigate its pharmacokinetic profile in rabbit aqueous humor. Methods: DEX cubosomes was prepared by the method of high-pressure homogenization, and its particle size was determined by the laser particle sizer, and the microstructure observed by cryo-TEM. In addition, Draize method was used to evaluate the ocular irritation of DEX cubosomes. Finally, aqueous humor microdialysis was utilized to evaluate its pharmacokinetics in rabbits. Results: Average diameter of DEX cubosomes was about 200 nm, and the cubic structure of the particles was evident under the cryo-TEM. It was indicated by Draize scores that this dosage form exhibited excellent ocular tolerance. Results of pharmacokinetic profiles in aqueous humor showed that AUC_(0→240) and c_(max) of the rabbit group administered with DEX cubosomes were significantly higher than those of the control group( DEX sodium phosphate eye drops), with AUC_(0→240) of the formulation Fl( 10% oil content) and F2(20% oil content) is being about 1. 8 and 2. 9 times higher than those of the control group, respectively( P <0. 05). Conclusion: The novel ocular drug delivery system of DEX cubosomes was capable of increasing significantly the drug concentration in aqueous humor, and improving the ocular bioavailability.