Preparation of Thiomer Microparticles and In Vitro Evaluation of Parameters Influencing Their Mucoadhesive Properties

Autor:	E. J. Zirm, Karin Albrecht, Wolfgang Schlocker, Thomas F. Palmberger, Andreas Bernkop-Schnürch
Rok vydání:	2006
Předmět:	Surface Properties Swine Acrylic Resins Pharmaceutical Science In Vitro Techniques Hydrolysis Drug Delivery Systems Intestinal mucosa Enzymatic hydrolysis Drug Discovery Mucoadhesion Animals Cysteine Sulfhydryl Compounds Intestinal Mucosa Particle Size Microparticle Pharmacology chemistry.chemical_classification Drug Carriers Chromatography Chemistry Thiomer Organic Chemistry Adhesiveness Polymer Fluoresceins In vitro Biochemistry Microscopy Electron Scanning
Zdroj:	Drug Development and Industrial Pharmacy. 32:1149-1157
ISSN:	1520-5762 0363-9045
Popis:	It was the aim of this study to develop mucoadhesive microparticulate delivery systems based on thiomers and to investigate parameters influencing their mucoadhesive properties. Microparticles were prepared via coazervation of thiolated or unmodified polycarbophil with fluorescein-diacetate as marker. The protective effect of the polymers toward enzymatic hydrolysis by intestinal enzymes was investigated. Mucoadhesion studies with microparticles, applied in dry and prehydrated form, were performed by ascertaining their residence time on intestinal mucosa. Furthermore, the influence of the amount of thiol groups on mucoadhesion was studied in vitro. Results showed that in comparison to unmodified polycarbophil, thiolated polycarbophil provided a more than 3-fold higher protective effect for the incorporated marker fluorescein-diacetate toward hydrolysis. When being applied in dry form 23.4 +/- 4.8% of the fluorescence marker being embedded in thiomer microparticles remained adhering to the intestinal mucosa within 3 h. In contrast, only 11.6 +/- 2.0% of the marker remained on the mucosa, when the thiomer microparticles were applied in prehydrated form. In addition, tests performed to assess the impact of the amount of thiol groups pointed out that a high amount of thiol groups is advantageous in order to further improve mucoadhesive properties. This knowledge should contribute to the design of highly efficient drug delivery systems being based on thiomer microparticles.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::db2198d2c2d2678df239baa69a779001 https://doi.org/10.1080/03639040600712334 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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