title: Swelling and drug release behavior of tablets coated with aqueous hydroxypropyl methylcellulose phthalate (HPMCP) nanoparticles.
abstract: Organic solvent-based enteric coating technology using hydroxypropyl methyl cellulose phthalate (HPMCP) has been developed for many years due to low water solubility of HPMCP. In this work, aqueous HPMCP nanoparticles (HPMCP-NPs) were prepared by neutralization emulsification method using HPMCP powder and ammonium hydroxide (NH(4)OH) in the absence of any organic solvent and emulsifier. Tablets for enteric use were coated with HPMCP-NP dispersions having different degree of neutralization that was manipulated by ion-exchange process. Disintegration and dissolution behavior of coated tablets were investigated using UV-visible spectrophotometer based on USP method (pH 1.2 and at 37 degrees C) and simulated intestinal fluid (pH 6.8 and at 37 degrees C for 60 min), respectively. The ion-exchange process, which was directly achieved by the protonation of dissociated carboxylic acid group of the aqueous HPMCP-NPs, was introduced as a useful way to control the release rate of drug and hydrophobic nature of HPMCP coating layer with a view for pharmaceutical application. The drug release and swelling were increased with increase in conductivity of aqueous HPMCP-NPs. On the other hand, particle size and polydispersity were decreased with increase in degree of neutralization.
authors.affiliation: Nanosphere Process and Technology Laboratory, Division of Chemical Engineering and Biotechnology, Yonsei University, 134 Shinchon-dong, Sudaemoon-ku, 120-749, Seoul, South Korea.
authors.forename: Il Hyuk
authors.initials: IH
authors.lastname: Kim
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Park
authors.forename: In Woo
authors.initials: IW
authors.lastname: Cheong
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Kim
mesh_terms: D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000493:pharmacokinetics*; D043942:Nanotubes / Q000737:chemistry*; D013608:Tablets, Enteric-Coated / Q000737:chemistry* / Q000493:pharmacokinetics*
chemical_list: D013608:Tablets, Enteric-Coated; D008747:Methylcellulose; C053309:hydroxypropyl methylcellulose phthalate