Numerous novel ophthalmic drug delivery systems have been developed to achieve a higher bioavailability of drugs. Some of these may be in situ gelling systems, microspheres, nanoparticles, liposomes and ocular inserts. The natural polymers include botanical polysaccharides (guar gum, locust bean), microbial polymer polysaccharides (dextran), algal polysaccharides (sodium alginate, carrageenan) and animal polysaccharides (sodium hyaluronate). Natural gums & their derivatives have been used as gel forming agents in the form of matrices. Natural gums are frequently preferred to synthetic materials due to their safety, economy and availability. One such natural material would be Sterculia foetida gum (SFG). The ocular use of this formulation as matrix minitablet (MT) was considered in the present work to possibly improve the bioavailability of ocular drugs.
