title: Poly(lactic acid)-coated mesoporous silica nanosphere for controlled release of venlafaxine.
abstract: Two types of mesoporous silica nanospheres (MSNs) were synthesized for use as controlled-release agents. One was prepared by grafting with 5,6-dihydroxyhexylsilane (DH-MSN) and the other one by further coating with cholic acid-crosslinked poly(lactic acid) (CA-PLA-MSN). We studied the release of the antidepressant venlafaxine from each of the materials in simulated gastric fluid (SGF), in simulated gastric acid solution (SGA), and in simulated intestinal fluid without pancreatin (SIF). The CA-PLA-MSN material was able to significantly delay the release of the drug in intestinal condition compared with gastric acid surrounding due to the fast decomposition rate of PLA in gastric acid. Moreover, it successfully avoided the initial burst to a certain extent in SGF. The enzyme pepsin played a favorable obstruct role in both DH-MSN and CA-PLA-MSN systems to reduce release rate. A model based on Weibull model was built to fit the release results, and based on it, the mechanisms about release processes were brought out tentatively.
authors.affiliation: Department of Chemistry, Iowa State University, Ames, IA, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.forename: Igor I
authors.initials: II
authors.lastname: Slowing
authors.forename: Yulin
authors.initials: Y
authors.lastname: Huang
authors.forename: Brian G
authors.initials: BG
authors.lastname: Trewyn
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.forename: Honglai
authors.initials: H
authors.lastname: Liu
authors.forename: Victor S-Y
authors.initials: VS
authors.lastname: Lin
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003511:Cyclohexanols / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry*; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D000069470:Venlafaxine Hydrochloride
chemical_list: D020099:Coated Materials, Biocompatible; D003511:Cyclohexanols; D003692:Delayed-Action Preparations; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D012822:Silicon Dioxide; D000069470:Venlafaxine Hydrochloride