Poly(ethylene glycol) methacrylate/dimethacrylate hydrogels for controlled release of hydrophobic drugs

dc.contributor.author	DiRamio, JA	en
dc.contributor.author	Kisaalita, WS	en
dc.contributor.author	Majetich, GF	en
dc.contributor.author	Shimkus, JM	en
dc.date.accessioned	2014-06-06T06:46:17Z
dc.date.available	2014-06-06T06:46:17Z
dc.date.issued	2005	en
dc.identifier.issn	87567938	en
dc.identifier.uri	http://dx.doi.org/10.1021/bp0495670	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/2891
dc.subject.other	Hormones	en
dc.subject.other	Hydrogels	en
dc.subject.other	Insulin	en
dc.subject.other	Molecular weight	en
dc.subject.other	pH effects	en
dc.subject.other	Polyethylene glycols	en
dc.subject.other	Polymers	en
dc.subject.other	Hydrophobic drugs	en
dc.subject.other	Non-Fickian diffusion	en
dc.subject.other	Ph buffers	en
dc.subject.other	Steroid hormones	en
dc.subject.other	Drug products	en
dc.subject.other	acrylic acid derivative	en
dc.subject.other	cross linking reagent	en
dc.subject.other	drug carrier	en
dc.subject.other	estradiol	en
dc.subject.other	insulin	en
dc.subject.other	macrogol derivative	en
dc.subject.other	poly(ethylene glycol) dimethacrylate	en
dc.subject.other	poly(ethylene glycol) methacrylate polymer	en
dc.subject.other	poly(ethylene glycol)-dimethacrylate	en
dc.subject.other	article	en
dc.subject.other	biochemistry	en
dc.subject.other	chemistry	en
dc.subject.other	hydrogel	en
dc.subject.other	hydrophobicity	en
dc.subject.other	methodology	en
dc.subject.other	pH	en
dc.subject.other	temperature	en
dc.subject.other	Acrylates	en
dc.subject.other	Biochemistry	en
dc.subject.other	Cross-Linking Reagents	en
dc.subject.other	Drug Carriers	en
dc.subject.other	Estradiol	en
dc.subject.other	Hydrogel	en
dc.subject.other	Hydrogen-Ion Concentration	en
dc.subject.other	Hydrophobicity	en
dc.subject.other	Insulin	en
dc.subject.other	Polyethylene Glycols	en
dc.subject.other	Temperature	en
dc.title	Poly(ethylene glycol) methacrylate/dimethacrylate hydrogels for controlled release of hydrophobic drugs	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/bp0495670	en
heal.publicationDate	2005	en
heal.abstract	Hydrogels have been successfully used to entrap hydrophilic drugs and release them in a controlled fashion; however, the entrapment and release of hydrophobic drugs has not been well studied. We report on the release characteristics of a model hydrophobic drug, the steroid hormone estradiol, entrapped in low (MW 360/MW 550) and high (MW 526/MW 1000) molecular weight poly(ethylene glycol) methacrylate (PEG-MA)/dimethacrylate (PEG-DMA) hydrogels. The cross-linking ratio, temperature, and pH ranged from 10:1 to 10:3, from 33 to 41°C, and from 2 to 12, respectively. The gelation of the PEG-MA/PEG-DMA hydrogel was initiated with UV irradiation. The absence of poly(glutamic acid) in the hydrogel formulation resulted in a loss of pH sensitivity in the acidic range, which was displayed by the hydrogels' similarities in swelling ratios in the pH buffers of pH 2, 4, and 7. Use of high molecular weight polymers resulted in a higher hydrogel swelling (300%) in comparison to the low molecular weight polymers. Drug size was found to be a significant factor. In comparison to 100% estradiol (MW 272) release, the fractional release of insulin (MW 5733) was 12 and 24% in low and high molecular weight gels at pH 2, respectively, and 17% in low molecular weight gels at pH 7. On the release kinetics of the estradiol drug, the hydrogels displayed a non-Fickian diffusion mechanism, which indicated that the media penetration rate is in the same range as the drug diffusion. The synthesis, entrapment, and release of estradiol by the PEG-MA/PEG-DMA hydrogels proved to be successful, but the use of ethanol in the buffers to promote the hydrophobic release of the estradiol in the in vitro environment caused complications, attributed to the process of transesterification. © 2005 American Chemical Society and American Institute of Chemical Engineers.	en
heal.journalName	Biotechnology Progress	en
dc.identifier.issue	4	en
dc.identifier.volume	21	en
dc.identifier.doi	10.1021/bp0495670	en
dc.identifier.spage	1281	en
dc.identifier.epage	1288	en