title: Enteric-coating of pulsatile-release HPC capsules prepared by injection molding.
abstract: Capsular devices based on hydroxypropyl cellulose (Klucel® LF) intended for pulsatile release were prepared by injection molding (IM). In the present work, the possibility of exploiting such capsules for the development of colonic delivery systems based on a time-dependent approach was evaluated. For this purpose, it was necessary to demonstrate the ability of molded cores to undergo a coating process and that coated systems yield the desired performance (gastric resistance). Although no information was available on the coating of IM substrates, some issues relevant to that of commercially-available capsules are known. Thus, preliminary studies were conducted on molded disks for screening purposes prior to the spray-coating of HPC capsular cores with Eudragit® L 30 D 55. The ability of the polymeric suspension to wet the substrate, spread, start penetrating and initiate hydration/swelling, as well as to provide a gastroresistant barrier was demonstrated. The coating of prototype HPC capsules was carried out successfully, leading to coated systems with good technological properties and able to withstand the acidic medium with no need for sealing at the cap/body joint. Such systems maintained the original pulsatile release performance after dissolution of the enteric film in pH 6.8 fluid. Therefore, they appeared potentially suitable for the development of a colon delivery platform based on a time-dependent approach.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Sezione di Tecnologia e Legislazione Farmaceutiche "Maria Edvige Sangalli", Università degli Studi di Milano, 20133 Milan, Italy; Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA. Electronic address: elena.macchi@unimi.it.
authors.forename: E
authors.initials: E
authors.lastname: Macchi
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Sezione di Tecnologia e Legislazione Farmaceutiche "Maria Edvige Sangalli", Università degli Studi di Milano, 20133 Milan, Italy. Electronic address: lucia.zema@unimi.it.
authors.forename: L
authors.initials: L
authors.lastname: Zema
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Sezione di Tecnologia e Legislazione Farmaceutiche "Maria Edvige Sangalli", Università degli Studi di Milano, 20133 Milan, Italy. Electronic address: alessandra.maroni@unimi.it.
authors.forename: A
authors.initials: A
authors.lastname: Maroni
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Sezione di Tecnologia e Legislazione Farmaceutiche "Maria Edvige Sangalli", Università degli Studi di Milano, 20133 Milan, Italy. Electronic address: andrea.gazzaniga@unimi.it.
authors.forename: A
authors.initials: A
authors.lastname: Gazzaniga
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA. Electronic address: lfelton@unm.edu.
authors.forename: L A
authors.initials: LA
authors.lastname: Felton
mesh_terms: D002214:Capsules; D002482:Cellulose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods*; D013608:Tablets, Enteric-Coated
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D013608:Tablets, Enteric-Coated; D002482:Cellulose; C008079:hydroxypropylcellulose
keywords: Capsular device; Enteric coating; Injection molding; Oral colon delivery; Oral pulsatile release; Swellable/erodible polymers