Chitosan modified 5-fluorouracil nanostructured lipid carriers for treatment of diabetic retinopathy in rats: A new dimension to an anticancer drug.

Diabetic retinopathy (DR) is one of the chronic complications of diabetes. It includes retinal blood vessels' damage. If untreated, it leads to loss of vision. The existing treatment strategies for DR are expensive, invasive, and need expertise during administration. Hence, there is a need to develop a non-invasive topical formulation that can penetrate deep to the posterior segment of retina and treat the damaged retinal vessels. In addition, it should also provide sustained release. In recent years, novel drug delivery systems (NDDS) have been explored for treating DR and found successful. In this study, chitosan (CS) modified 5-Fluorouracil Nanostructured Lipid Carriers (CS-5-FU-NLCs) were prepared by modified melt emulsification-ultrasonication method and optimized by Box-Behnken Design. The size, polydispersity index, zeta potential and entrapment efficiency of CS-5-FU-NLCs were 163.2 ± 2.3 nm, 0.28 ± 1.52, 21.4 ± 0.5 mV and 85.0 ± 0.2 %, respectively. The in vitro drug release and ex vivo permeation study confirmed higher and sustained drug release in CS-5-FU-NLCs as compared to 5-FU solution. HET-CAM Model ensured the non-irritant nature of CS-5-FU-NLCs. In vivo ocular studies of CS-5-FU-NLCs confirmed antiangiogenic effect of 5-FU by CAM model and diabetic retinopathy induced rat model, indicating successful delivery of 5-FU to the retina.

Harnessing the dual role of polysaccharides in treating gastrointestinal diseases: As therapeutics and polymers for drug delivery.

Polysaccharides (PS) represent a broad class of polymer-based compounds that have been extensively researched as therapeutics and excipients for drug delivery. As pharmaceutical carriers, PS have mostly found their use as adsorbents, suspending agents, as well as cross-linking agents for various formulations such as liposomes, nanoparticles, nanoemulsions, nano lipid carriers, microspheres etc. This is due to inherent properties of PS such as porosity, steric stability and swellability, insolubility in pH. There have been emerging reports on the use of PS as therapeutic agent due to its anti-inflammatory and anti-oxidative properties for various diseases. In particular, for Crohn's disease, ulcerative colitis and inflammatory bowel disease. However, determining the dosage, treatment duration and effective technology transfer of these therapeutic moieties have not occurred. This is due to the fact that PS are still at a nascent stage of development to a full proof therapy for a particular disease. Recently, a combination of polysaccharide which act as a prebiotic and a probiotic have been used as a combination to treat various intestinal and colorectal (CRC) related diseases. This has proven to be beneficial, has shown good in vivo correlation and is well reported. The present review entails a detailed description on the role of PS used as a therapeutic agent and as a formulation pertaining to gastrointestinal diseases.