Recent progress in alginate-based carriers for ocular targeting of therapeutics

Eye is one of the susceptible organs of the human body which is associated with several internal organs including the brain. Due to the protective mechanisms of body and ocular barrier properties, the area of ocular drug delivery presents a challenge to pharmaceutical researchers. Alginate is a naturally occurring polysaccharide obtained from marine brown seaweeds and bacterial sources. According to the Food and Drug Administration, (FDA) alginate is generally recognized as safe (GRAS). It is widely used as a gelling agent and thickener in the food industries. In the field of drug delivery, alginate is extensively investigated as an excipient. In ocular targeting of therapeutics, sodium alginate offers many advantages including ion sensitive in situ gelation, non-toxic and biodegradable behaviour in combination with mucoadhesive nature of the polymer. The instant gelation ability of alginate allows it to increase the ocular residence time and enhances the ocular drug bioavailability reducing the requirement of frequent administration of drug. The abundant availability and attractive physicochemical properties of alginate has encouraged pharmaceutical scientists to explore newer strategies in ocular drug targeting. In this review, the efficacy of alginate in delivering various therapeutic agents has been discussed.