Application of lipid microsphere drug delivery system to steroidal ophthalmic preparation

The applicability of a lipid microsphere drug delivery system to ophthalmic preparations was examined using a lipid microsphere containing hydrocortisone 17-butyrate 21-propionate (HBP). 3H-labelled HBP ophthalmic suspension and 3H-labelled HBP lipid microsphere were applied to rabbit eyes, and the eyes were enucleated after 1 and 3 hours to determine 3H-labelled HBP levels in the ocular tissues. The lipid microsphere proved to deliver the drug to the anterior ocular tissues more significantly than the ophthalmic suspension. It is suggested that the lipid microsphere ophthalmic preparation of various lipophilic drugs including steroids may be useful as one of the drug delivery systems for ophthalmic therapy.