For the past few decades, there has been a considerable research interest in the area of drug delivery using particulate delivery systems as carriers for small and large molecules. Particulate systems like nanoparticles have been used as a physical approach to alter and improve the pharmacokinetic and pharmacodynamic properties of various types of drug molecules. They have been used in vivo to protect the drug entity in the systemic circulation, restrict access of the drug to the chosen sites and to deliver the drug at a controlled and sustained rate to the site of action. Various polymers have been used in the formulation of nanoparticles for drug delivery research to increase therapeutic benefit, while minimizing side effects. Here, we review various aspects of nanoparticle formulation, characterization, effect of their characteristics and their applications in delivery of drug molecules and therapeutic genes.

No abstract

The purpose of this study was to examine the effect of charge ratio on the formation and properties of the chitosan (CS)-dextran sulfate (DS) nanoparticles developed for the delivery of water-soluble small and large molecules, including proteins. Rhodamine 6G (R6G) and bovine serum albumin (BSA) were chosen as model molecules. CS-DS nanoparticles were formulated by a complex coacervation process under mild conditions. The influence of formulation and process variables, including the charge ratio of the 2 ionic polymers, on particle size, zeta potential, and nanoparticle entrapment of R6G and BSA was studied. The in vitro release of R6G and BSA was also evaluated, and the integrity of BSA in the release fraction was assessed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Depending on the concentration and charge ratio of DS and CS, nanoparticles with varied size (>or=244 nm) and zeta potential (-47.1-60 mV) were obtained. High entrapment efficiency (98%) was achieved for both R6G and BSA when the charge ratio of the 2 ionic polymers was greater than 1.12. The release of both R6G and BSA from nanoparticles was based on the ion-exchange mechanism. BSA showed much slower continuous release for up to 7 days while still maintaining its integrity for an extended period. The CS-DS nanoparticles developed based on the modulation of charge ratio show promise as a system for controlled delivery of both small and large molecules, including proteins.

No abstract

No abstract