A Review on Ophthalmic In Situ Gels

Abstract

The field of ocular drug delivery is one of the most challenging and interesting field for pharmaceutical scientist. In ophthalmic in situ gels various polymers are used. Generally hydrogels are used. These polymers will increase solution viscosity the field of ocular drug delivery is one of the most challenging and interesting field for pharmaceutical scientist. From last 10 to 20 years the field has been significantly improved 1 . Due the site of delicacy and the many restrains of the site of application caution has to be taken during formulation of new product 2. According to physiology of eye this organ is impermeable to foreign substances. It is difficult to formulation to cross the protective barriers of eye so that drug reaches to site of action in sufficient concentration. 1 Novel drug delivery systems aimed to overcome the biological barrier which can obstruct efficient ocular drug delivery. 3 Crossing protective barrier without damaging the permanent tissue is major challenge to formulator during formulation. Some common diseases which are cured by topical drug delivery are blepharitis, conjunctivitis, keratitis, trachoma, glaucoma etc 4 . The major disadvantages of conventional formulation such as solutions, suspensions, emulsions, ointments etc. are poor bioavailability, increased precorneal elimination, high variability in efficacy respectively. 5 Because of convenience and safety for ophthalmic chemotherapy optical application of drug is most preferred formulation.

Gel-Based Materials for Ophthalmic Drug Delivery

“…They are mainly applied as tear substitutes in the treatment of dry eye because they present numerous drawbacks, which limit their use for the administration of ophthalmic drugs. Gel eye drops do not allow accurate and reproducible drug administration and can cause blurred vision, crusting on the eyelids, and tearing [9][10][11]. In this context, this review intends to focus attention on the gel-based materials used in the treatment of eye diseases.…”

“…They are mainly applied as tear substitutes in the treatment of dry eye because they present numerous drawbacks, which limit their use for the administration of ophthalmic drugs. Gel eye drops do not allow accurate and reproducible drug administration and can cause blurred vision, crusting on the eyelids, and tearing [9][10][11]. Hydrogels enable the incorporation of a variety of ophthalmic pharmaceuticals, are retained in the eye, and are well tolerated compared to conventional pharmaceutical formulations such as ointments, while simultaneously decreasing the side effects due to systemic absorption [4].…”

“…They are mainly applied as tear substitutes in the treatment of dry eye because they present numerous drawbacks, which limit their use for the administration of ophthalmic drugs. Gel eye drops do not allow accurate and reproducible drug administration and can cause blurred vision, crusting on the eyelids, and tearing [9][10][11]. In general, these formulations consist of cellulose derivatives, such as carboxymethylcellulose (CMC) [12,13], hydroxypropylmethylcellulose (HPMC) [14,15], carbomer (carbopol), or hyaluronic acid (HA) [16][17][18].…”