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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1999-10-13
pubmed:abstractText
17beta-Estradiol-loaded microparticles using poly-(D, L-lactide-co-glycolide) polymer (PLG) were prepared by a modified spray-drying method and the effects of gamma-irradiation on drug substance, polymer and microparticles were investigated. Irradiation doses ranging from 5.1 to 26.6 kGy were applied using a 60Co-radiation source. 17beta-Estradiol drug substance showed excellent stability against gamma-irradiation in the investigated dose range, whereas microencapsulated estradiol seems to be converted to conjugation products with PLG, and to a lesser extent to the degradation product 9,11-dehydroestradiol. The weight-average molecular weight of the PLG polymers decreased with increasing irradiation dose while polydispersity indices (M(w)/M(n)) remained nearly unchanged, compatible with a random chain scission mechanism in lactide/glycolide-copolymer degradation. In vitro drug release studies showed accelerated kinetics with increasing irradiation doses due to dose dependent polymer degradation. Microbiological process monitoring showed decreasing bioburden with increasing spraying time, which was successfully further reduced by applying irradiation sterilization. Microencapsulated test spore suspensions of Bacillus pumilus ATCC 27142, the official test specimen for the gamma-sterilization process, revealed effective reduction of bioburden, confirming its published D(10) value. In conclusion, our studies demonstrated efficacy of gamma-irradiation as terminal sterilization method for poly-(D,L-lactide-co-glycolide) polymer-based drug delivery systems. The sterilization conditions need to be carefully adjusted for the final dosage form.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0168-3659
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
203-17
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Gamma irradiation for terminal sterilization of 17beta-estradiol loaded poly-(D,L-lactide-co-glycolide) microparticles.
pubmed:affiliation
Schwarz Pharma AG, D-40789, Monheim, Germany.
pubmed:publicationType
Journal Article