Design and development of artemisinin and dexamethasone loaded topical nanodispersion for the effective treatment of age-related macular degeneration.

Age-related macular degeneration (AMD) is a disease affecting the macula by the new blood vessels formation. AMD is widely treated with a combination of anti-angiogenic and anti-vascular endothelial growth factor (VEGF) agents. The topical administration of nanodispersions showed enhanced ocular residence time with controlled and prolonged drug delivery to the disease site at the back of the eye. In the present study we developed and characterized nanodispersion containing anti-angiogenic (artemisinin) and anti-VEGF agent (dexamethasone) for the topical ocular administration in order to obtain a required drug concentration in the posterior part of the eye. The nanodispersions were prepared with varying concentration of polymer, polyvinyl pyrrolidone K90 and polymeric surfactant, Poloxamer 407. The nanodispersions were found to be smooth and spherical in shape with a size range of 12-26 nm. In-vitro drug release studies showed the 90-101% of artemisinin and 55-103% of dexamethasone release from the nanodispersions. The blank formulation with a high concentration of polymer and polymeric surfactant showed an acceptable level of haemolysis and DNA damage. The chorioallantoic membrane assay suggested that the nanodispersion possess good anti-angiogenic effect. Hence the formulated artemisinin and dexamethasone nanodispersion may have the great potential for the AMD treatment.

Chitosan stabilized camptothecin nanoemulsions: Development, evaluation and biodistribution in preclinical breast cancer animal mode.

Clinical use of camptothecin (CPT) is hindered due to its poor water and oil solubility, active lactone ring instability and non-targeted toxicity. Recently we reported formulation of camptothecin microemulsions with increased solubility for the improved treatment of breast cancer. In this research chitosan stabilized camptothecin nanoemulsions (CHI-CPT-NEs) were formulated improve the cancer targeting efficiency of CPT. The developed NEs were characterized for their droplet size distribution, stability in plasma and evaluated for in-vitro drug release, in-vivo targeting potential, in-vitro hemolytic potential, cytotoxicity, genotoxicity and in-vivo biodistribution. The CHI-CPT-NEs showed uniform droplet size distribution, extended drug release (61.65±1.57% at 24h), tolerable hemolytic potential (16.4±1.4%), significant cytotoxicity (178±4.3ng/ml) against MCF-7 cancer cells and low DNA damage to lymphocytes. In-vivo biodistribution study conducted in 4T1-breast tumor xenograft BALB/c mice showed that 2495.22±174.66ng/gm of camptothecin was passively targeted to breast cancer by CHI-CPT-NEs compared to the non-stabilized nanoemulsion (1677.58±134.21ng/gm). Thus, passive targeting of developed CHI-CPT-NEs may provide a promising approach for the efficient breast cancer therapy.