Preparation of pH-sensitive carboxymethyl cellulose/bovine serum albumin composite particles and evaluation of their drug delivery capacity

Abstract

This study developed structurally stable, high-performance drug delivery composite particles using a simple and portable electrostatic self-assembly method involving carboxymethyl cellulose (CMC) and bovine serum albumin (BSA). Adjusting the system’s pH to below the isoelectric point of BSA induced a positive charge, promoting electrostatic attraction and assembly with CMC. The resulting composite particles were characterized, and the factors influencing their properties were systematically analyzed. Amoxicillin and theophylline were selected as model drugs to assess the sustained-release performance of the composite particles. The results indicated that the particles exhibited uniform morphology, with an average size of 308 nm and a dispersity (Ð) of 0.184 before heating. After heating, the particle size increased to 412 nm, with a Ð of 0.196. The encapsulation efficiencies for amoxicillin and theophylline were 69 and 53%, respectively, with the sustained-release profile demonstrating efficient drug-loading and sustained-release capabilities. This study highlights the potential of CMC as a natural, high molecular weight material for small molecule drug delivery and emphasizes the developmental prospects of composite systems integrating proteins like BSA with polysaccharides.