Abstract

HYDROGELS – AN OCULAR DRUG DELIVERY SYSTEM: A REVIEW

Ankit Majie, Anwesh Bhowmick, Priyanka Ray and Prapti Chakraborty*

ABSTRACT

The conventional marketed ocular formulations like eye drops, emulsions, ointments, suspensions, etc., suffer from a lower residence time of fewer than two minutes, leading to rapid elimination and a shorter duration of action. Thus, a formulation is needed which has more excellent residence time, better shelf life, minimal systemic absorption, and reduced administration frequency of dosing. To suffice these needs, there is a requirement for the hydrogel formulation. This hydrogel formulation can be used as soft contact lenses, artificial tear, ocular wound repairing, and treat various bacterial and viral eye infections that require prolonged ocular residence time and local action. The various types of hydrogel that can be formulated include the physically cross-linked and chemically cross-linked hydrogel system; and the stimuli-responsive and in-situ gel-forming system. These formulations of the hydrogel can be formulated by various polymer systems, including hyaluronic acid, chitosan, methylcellulose, gelatine, and alginates. The various formulation methodologies include bulk, solution, suspension polymerization, and grafting techniques. The formulated ocular hydrogel can be evaluated by determining pH, rheological study, gelling capacity, drug release study in-vivo, stability study, diffusion study ex-vivo, evaluation of sterility, observation of morphology, and determination of gelation temperature and gelation time.

Keywords: Residence time, Polymerization, Cross-linked, In-situ gel, Shelf life.