title: Relationships between surface free energy, surface texture parameters and controlled drug release in hydrophilic matrices.
abstract: The study of controlled release and drug release devices has been dominated by considerations of the bulk or average properties of material or devices. Yet the outermost surface atoms play a central role in their performance. The objective of this article has been to characterize the surface of hydrophilic matrix tablets using the contact angle (CA) method to ascertain the surface free energy, and atomic force microscopy (AFM) and confocal microscopy (CM) for the physical characterization of the surface of the hydrophilic matrix. The surface free energy results obtained show that hydroxypropylmethylcellulose K15M hinders the spreading of water on the surface of the tablet, such that the concentration of HPMC K15M increases the reaction rate of the hydrophobic interactions between the chains of HPMC K15M which increases with respect to the rate of penetration of water into the tablet. In this study, we developed a new method to characterize the swelling of the tablets and established a relationship between the new method based on microswelling and the swelling ratio parameter. The surface texture parameters have been determined and the morphology of the tablets of the different formulations and the evolution of the surface morphology after interacting with the water, swelling and forming a gel layer were characterized. This work represents significant progress in the characterization of matrix tablets.
authors.affiliation: Pharmacy and Pharmaceutical Technology Department, Universitat de Barcelona, Barcelona, Spain; Recipharm, Parets del Vallès, Barcelona, Spain. Electronic address: jaumesauri@hotmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Saurí
authors.affiliation: Pharmacy and Pharmaceutical Technology Department, Universitat de Barcelona, Barcelona, Spain; IDIBELL-UB Research Group: Pharmacotherapy, pharmacogenomics & Pharmaceutical Technology, Barcelona, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Suñé-Negre
authors.affiliation: Centres Científics i Tecnològics de la Universitat de Barcelona (CCiTUB), Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Díaz-Marcos
authors.affiliation: Centres Científics i Tecnològics de la Universitat de Barcelona (CCiTUB), Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Vilana
authors.affiliation: Lab. Kern Pharma, Barcelona, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Millán
authors.affiliation: Pharmacy and Pharmaceutical Technology Department, Universitat de Barcelona, Barcelona, Spain; IDIBELL-UB Research Group: Pharmacotherapy, pharmacogenomics & Pharmaceutical Technology, Barcelona, Spain.
authors.forename: J R
authors.initials: JR
authors.lastname: Ticó
authors.affiliation: Pharmacy and Pharmaceutical Technology Department, Universitat de Barcelona, Barcelona, Spain; IDIBELL-UB Research Group: Pharmacotherapy, pharmacogenomics & Pharmaceutical Technology, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Miñarro
authors.affiliation: Pharmacy and Pharmaceutical Technology Department, Universitat de Barcelona, Barcelona, Spain; IDIBELL-UB Research Group: Pharmacotherapy, pharmacogenomics & Pharmaceutical Technology, Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Pérez-Lozano
authors.affiliation: Pharmacy and Pharmaceutical Technology Department, Universitat de Barcelona, Barcelona, Spain; IDIBELL-UB Research Group: Pharmacotherapy, pharmacogenomics & Pharmaceutical Technology, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: García-Montoya
mesh_terms: D002216:Captopril / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D065347:Hypromellose Derivatives / Q000737:chemistry; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D012995:Solubility; D013499:Surface Properties; D013607:Tablets / Q000737:chemistry*; D017155:Wettability
chemical_list: D003692:Delayed-Action Preparations; D005079:Excipients; D013607:Tablets; D065347:Hypromellose Derivatives; D002216:Captopril
keywords: Drug release; Hydrophilic matrices; Microswelling; Surface analysis; Surface free energy; Surface texture parameters