Abstract
Purpose:
Our primary aim was to develop and characterize topical dexamethasone-loaded polymeric nanomicelles of various mean sizes (size <80nm).We further determined the effect of nanomicelle size on dexamethasone (DEX) transport across the ocular static barriers.
Methods:
Low molecular weight diblock co-polymers, PCL-mPEG were synthesized by ring opening polymerization. Polymers were characterized by H1 NMR, IR spectroscopy, gel permeation chromatography, critical micelle concentration (CMC) and cytotoxicity studies in corneal, conjunctival and retinal cell-lines. DEX-loaded nanomicelles were prepared by modified-film hydration method. The optimized formulation was characterized for solubility of DEX, micelle size and PDI, morphology, in vitro release and in vitro transport across conjunctival cell line. The formulation was also subjected to ex vivo transport across excised rabbit sclera to determine influence of micelle size on DEX transport across the static barrier
Results:
The optimized nanomicelle formulation exhibited mean size in range of 10-15nm (DEXMA), 25-30nm (DEXMB) and 55-60nm (DEXMC) with unimodel size distribution and low polydispersity. DEX permeability across the excised rabbit sclera for DEXMA, DEXMB, DEXMC and DEX (Control) were found to be 2.65E-06, 3.00E-06, 1.52E-06 and 1.19E-06 cm/sec, respectively
Conclusions:
The permeability studies across the sclera indicates that the nanomicelles with average sizes 10nm and 25nm may have potential to deliver steroidal agents to the back of the eye following top
Keywords: 688 retina •
746 uveitis-clinical/animal model •
503 drug toxicity/drug effects