Swelling properties of various polymers used in controlled release systems

Vlachou, M; Naseef, H; Efentakis, M; Tarantili, PA; Andreopoulos, AG

dc.contributor.author	Vlachou, M	en
dc.contributor.author	Naseef, H	en
dc.contributor.author	Efentakis, M	en
dc.contributor.author	Tarantili, PA	en
dc.contributor.author	Andreopoulos, AG	en
dc.date.accessioned	2014-03-01T01:51:20Z
dc.date.available	2014-03-01T01:51:20Z
dc.date.issued	2001	en
dc.identifier.issn	0885-3282	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/26267
dc.subject	controlled release	en
dc.subject	swelling	en
dc.subject	diffusion	en
dc.subject	powder packing	en
dc.subject	porosity	en
dc.subject.classification	Engineering, Biomedical	en
dc.subject.classification	Materials Science, Biomaterials	en
dc.subject.other	HYDROGEL	en
dc.subject.other	NETWORKS	en
dc.title	Swelling properties of various polymers used in controlled release systems	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2001	en
heal.abstract	The effect of powder packing and porosity of specimens on the swelling properties of polymeric materials was studied, in various swelling liquids, such as distilled water and 0.1 N hydrochloric acid solution. Capsules, tablets and films of hydroxypropyl methylcellulose, poly(ethylene oxide) and sodium alginate were prepared, and their weight uptake after immersion into the above solutions was recorded as a function of time, in order to assess the swelling process. Measurements of some characteristics of the as-received powders were also performed in an attempt to classify the specimens prepared according to their porosity. Within the experimental conditions of this work, it was shown that the porosity of polymeric specimens is a dominant factor that controls their swelling behaviour. Increased porosity leads to fast initial rates of weight uptake and high extent of equilibrium swelling. On the other hand, dissolution and possible degradation of polymers susceptible to acid hydrolysis results in some variations from the above mentioned behaviour. With respect to the application in controlled release systems, the overall delivery rate from a polymeric specimen is expected to be a function of both swelling and disintegration characteristics of a specimen, and therefore, the weight uptake can be considered a measure of the release only in the case of polymers with low water solubility and increased stability to hydrolysis.	en
heal.publisher	TECHNOMIC PUBL CO INC	en
heal.journalName	JOURNAL OF BIOMATERIALS APPLICATIONS	en
dc.identifier.isi	ISI:000168103600001	en
dc.identifier.volume	15	en
dc.identifier.issue	4	en
dc.identifier.spage	293	en
dc.identifier.epage	306	en