Effects of conditions for preparing nanoparticles composed of aminoethylcarbamoyl-β-cyclodextrin and ethylene glycol diglycidyl ether on trap efficiency of a guest molecule

• Published in: International journal of pharmaceutics Vol. 311; no. 1; pp. 215 - 222
• Main Authors: Eguchi, Masaru, Du, Yong-Zhong, Ogawa, Yoshikatsu, Okada, Tomoko, Yumoto, Noboru, Kodaka, Masato
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 27.03.2006; Elsevier
• Subjects: Anilino Naphthalenesulfonates; beta-Cyclodextrins; Biological and medical sciences; Cyclodextrin; Drug Carriers; Emulsions; Epoxy Resins - chemistry; Fluorescent Dyes; General pharmacology; Hydrogen-Ion Concentration; Interfacial polyaddition reaction; Medical sciences; Nanoparticle; Nanostructures; Nanotechnology; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Polymers - chemistry; Surface-Active Agents - chemistry; Technology, Pharmaceutical - methods; Water - chemistry; Nanoparticle; Cyclodextrin; Interfacial polyaddition reaction; Ethylene glycol; Molecules; β-Cyclodextrin; Pharmaceutical technology; Ether; Efficiency; Microparticle; Inclusion compound; Polyaddition
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2005.12.015

Nanoparticles comprising copolymers of aminoethylcarbamoyl-β-cyclodextrin (AEC-β-CD) and ethylene glycol diglycidyl ether (EGDGE) are prepared by an interfacial polyaddition reaction in a miniemulsion system. Polymers are formed in a W/O emulsion containing 0.25–10.0% (w/w) water and 5.0% (w/w) surfactant (MO-3S, tetraglycerin monoester, HLB 8.8), where simple particles are predominantly obtained when the water content is 1.0% and 5.0%. Notably, nano-size small particles (diameter: 0.3 μm) are formed under the condition of 5.0% water and 5.0% surfactant, which have the highest β-CD contents (75.5 wt.%) and the most positive ζ-potential (53.6 mV). The ζ-potential measurement indicates that the obtained particles have positive charge due to protonation of their amino groups below around pH 10. Actually, uptake of 8-anilino-1-naphthalenesulfonic acid (ANS) bearing negative charge (SO 3 −) and moderate hydrophobicity depends on the magnitude of ζ-potential of the particles; viz., the particles with ζ-potential of 53.6 mV show the highest efficiency of uptake. The diameter and the β-CD contents are closely related with the water/surfactant ratio, and the ζ-potentials are dependent on both the diameter and the β-CD contents. Inclusion of ANS into the CD cavity of EGDGE/AEC-β-CD particles can be controlled by electrostatic interaction between ANS (negatively charged) and the particle (positively charged). Namely, synergistic effect of cavity-inclusion and electrostatic interaction can dominate the uptake of guest molecules by the particles.