Fabrication and investigation of oxidized- β- Cyclodextrin nanoparticle as a novel class pH responsive drug delivery vehicle

Oxidized β- cyclodextrin (O-β-CD) nanoparticle was synthesized using oxidation process and Amoxicillin trihydrate (AMOX) model drug was integrated both via Schiff base reaction (C = N bond) as well as inclusion into cavity of O-β-CD to evaluate pH-responsive drug release behavior. The drug loaded nanocarrier (AM-O-β-CD) was characterized and results showed this formation, encapsulation and morphological change with average particle size (398 ± 8.51nm), negative zeta potential values (-25.4 ± 1.54) and high entrapment efficiency (86.1%). The in vitro release behavior of AM-O-β-CD was evaluated in physiological buffer conditions (0.1 M PBS, pH 5.2, at 37°C). It was found that drug-loaded AM-O-β-CD showed sustain, prolonged much higher drug release profile (94.72%) in low pH than that of the pure drug (24.18%) in the same acidic medium. Release kinetics of drug loaded AM-O-β-CD was determined according to well-known mathematical models, revealing that in vitro release profile could be best expressed by Higuchi kinetic model as release data showed the highest linearity (R 2  = 0.967) so that drug release takes place due to both dissolution and diffusion as it is expected. As a result, it has been proven that the nanostructure has the potential to be pH sensitive drug carrier, especially for drugs containing NH 2 side groups in acidic environments.