2079450 9214446 PCTABS00015 Recognizing substances, epidermal growth factor, gelatin, collagen and hyaluronic acid, have been covalently bound to liposomal surfaces and utilized to attach liposomes onto a cellular target site. These "bioadhesive" liposomes offer several advantages in the area of topically and locally administered free drug. These advantages include the mutual protection of both the drug and biological environment; an increase in drug bioavailability and retention at the target site; and improved adherence or adhesion to the designated target site.