RESUMO
Bietti's crystalline dystrophy (BCD) is an autosomal recessive chorioretinal degeneration caused by mutations in the CYP4V2 gene. It is characterized by cholesterol accumulation and crystal-like deposits in the retinas. Hydroxypropyl-ß-cyclodextrin (HP-ß-CyD) exerts therapeutic effects against BCD by reducing lysosomal dysfunction and inhibiting cytotoxicity in induced pluripotent stem cell (iPSC)-RPE cells established from patient-derived iPS cells. However, the ocular retention of HP-ß-CyD is low and needs to be improved. Therefore, this study used a viscous agent to develop a sustained-release ophthalmic formulation containing HP-ß-CyD. Our results suggest that HP-ß-CyD-containing xanthan gum has a considerably higher sustained release capacity than other viscous agents, such as methylcellulose and sodium alginate. In addition, the HP-ß-CyD-containing xanthan gum exhibited pseudoplastic behavior. It was less cytotoxic to human retinal pigment epithelial cells compared with HP-ß-CyD alone. Furthermore, the slow release of HP-ß-CyD from xanthan gum caused a sustained decrease in free intracellular cholesterol. These results suggest that xanthan gum is a useful substrate for the sustained release formulation of HP-ß-CyD, and that HP-ß-CyD-containing xanthan gum has potential as an eye drop for BCD treatment.
