Microfibrillar polymeric ocular inserts for triamcinolone acetonide delivery

Despite eye drops generally represent the most convenient, simple and patient-friendly formulations to treat ocular diseases, they suffer from poor retention on the ocular surface and low drug bioavailability leading to the necessity of prolonged and continuous treatment over time. Therefore, ocular insert could represent an innovative way to benefit from ocular topical administration while minimizing all the relevant limitation related to this route of administration. Polymeric non-erodible mucoadhesive ocular inserts should be comfortable and should rapidly adhere on the ocular surface, remain in situ for prolonged period, assure a reproducible and controlled drug release as well as act as transcorneal absorption promoters. In this study, a well-known aliphatic polyester, poly(1,4-butylene succinate) (PBS), was used as starting material to produce hydrophobic microfibrillar scaffolds by means of electrospinning technique. Plasma-assisted chemical surface functionalization of the PBS scaffolds with appropriate biopolymers (inulin, alpha,beta-poly(N-2-hydroxyethyl)-D,L-aspartamide, heparin) was carried out to confer to the final ocular inserts ad hoc properties as wettability, mucoadhesion and cyto-compatibility on human corneal epithelial cells, by improving surface hydrophilicity without modifying the bulk properties of the material. The lipophilic drug triamcinolone acetonide was loaded into the obtained ocular insert and release studies were carried out to demonstrate the ability of drug loaded inserts to release the active until 30 days.