Design, Development and Evaluation of Paclitaxel Nanoparticles for Intra Nasal Drug Delivery

Abstract

Delivery of drugs to brain is most challenging in the neuro pharmaceutical research. Brainis surrounded by stringent anatomical barrier i.e. blood brain barrier (BBB), which expressed number of efflux transporters on its surface and limits the entry of variety of neuro pharmaceutical to the brain which make the management of CNS disorders refractory to the available therapy. Hence, in view of proposed challenges, present investigation focused on the development of nano particulate carriers fictionalized with gutathione for delivering drug / marker compound to the brain through intra-nasal route.

In present exploration fluorescein sodium and paclitaxel were explored as a model compounds because of their low permeability across the BBB and also found to be a substrate for P-gp (P-glycoprotein) and multidrug resistance proteins which further restricts its entry to the brain.

In present investigation, nanoparticles of poly lactide co-glycolide (PLGA, 50:50) and human serum albumin (HSA) were developed using modified nanoprecipitation and modified desolvation technique. Further, fluorescein sodium and paclitaxel loaded nanoparticles were prepared and optimized for drug entrapment, particle size and drug release properties using Design of Experiments. Glutathione was appended on the surface of drug loaded nanoparticles using carbodiimide chemistry. Glutathione conjugated and un-conjugated nanoparticles were characterized for its size, drug entrapment, morphology, drug release profile and for in-vitro, ex-vivo and in vivo bio-distribution studies.

In-vitro drug release studies were performed using dialysis bag technique. The drug release from the nanoparticles exhibited Weibull pattern i.e. initial burst release followed by slower release over extended period of time. Ex-vivo permeation studies were conducted across sheep nasal mucosa using Franz diffusion cell. Results of the studies indicated that glutathione coupled nanoparticles showed higher permeability across the nasal mucosa as compared to unconjugated nanoparticles and drug dispersion indicating potential role of glutathione for increasing permeability of nanoparticles across the nasal mucosa. In-vivo studies were carried out using wistar rats and distribution of fluorescein sodium and paclitaxel loaded formulations were observed in blood, brain, liver, kidney, lungs and spleen organs followed by intranasal administration. Studies revealed that significantly higher (p<0.001) concentration of fluorescein sodium (two folds) / paclitaxel (five folds) was observed in brain and blood with glutathione conjugated nanoparticles as compared to un-conjugated nanoparticles and drug dispersion indicating higher transport of glutathione coupled nanoparticles across the nasal mucosa to blood and subsequently to the brain. For developed formulations histological studies of nasal mucosa on exposed rat were carried. Histological studies indicated that extent of nasal mucosal inflammation and damage is much lesser when administered as polymeric nanoparticles and glutathione further provides protection to the nasal mucosa indicated by lesser neutrophils and intact mucosal membrane depicted in histology of nasal mucosa. Results of acute toxicity studies proved the safety of the synthesized nanoparticles on nasal mucosa model. Overall, present research conducted systematic investigation strengthen our conception that, glutathione conjugated nanoparticles improves the transport of model compounds into the brain and as well as across the nasal mucosa and higher concentration of both the compounds was observed in blood as well as brain during in-vivo and bio-distribution studies.