PNIPAAM Immobilized Nanoparticles for Posterior Ocular Delivery

Abstract

Ocular drug delivery to the posterior segment of the eye is extremely challenging. The delivery of the pharmaceuticals is made difficult by the numerous barriers that are present in the eye, as well as the isolated nature of the eye. The eye also consists of efficient drainage routes that eliminate the drug that has entered the eye successfully. Because of these reasons, drug delivery to the posterior segment of the eye is challenging and complicated. As a result, conventional eye drops are an inefficient way to deliver the pharmaceuticals to the eye as <5% of the administered dose is delivered to the anterior segment of the eye, and a negligible amount is delivered to the posterior tissues. The work presented in this thesis focuses on the design, synthesis, and characterization of the PLGA nanoparticles as a drug delivery vehicle to treat diseases associated with the posterior segment of the eye. The slow-release formulation was developed using PLGA nanoparticles and synthesized by the Double Emulsion Method (W1-O-W2). The PLGA nanoparticles were optimized by following various protocols and formulations to obtain the highest encapsulation efficacy and desired particle size range by changing the intensity of sonication, speed of ultracentrifugation, composition, and amount of the stabilizer and PLGA nanoparticles. The nanoparticles showed a 97% encapsulation efficiency with Bovine Serum Albumin (BSA) and a particle size of 201 nm. The slow-release formulation was further developed by immobilization of the particles in a thermogelling PNIPAAM scaffold. In vitro drug release results suggest that PNIPAAM containing PLGA nanoparticles produced in this work has the potential to be further developed and used as a drug delivery vehicle for the posterior segment of the eye.