کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9918660 1557552 2005 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Controlled release of levonorgestrel from biodegradable poly(d,l-lactide-co-glycolide) microspheres: In vitro and in vivo studies
موضوعات مرتبط
علوم پزشکی و سلامت داروسازی، سم شناسی و علوم دارویی علوم دارویی
پیش نمایش صفحه اول مقاله
Controlled release of levonorgestrel from biodegradable poly(d,l-lactide-co-glycolide) microspheres: In vitro and in vivo studies
چکیده انگلیسی
Poly(d,l-lactide-co-glycolide) (PLG) biodegradable microspheres containing a contraceptive drug, levonorgestrel (LNG), were prepared using both the solvent evaporation method and a modified solvent extraction-evaporation method. The microspheres prepared with the solvent evaporation process had porous surfaces with low product yields and poor encapsulation efficiencies. On the other hand, the microspheres prepared using the modified solvent extraction-evaporation method were nonporous with encapsulation efficiencies close to 100%. In vitro drug release showed the nonporous microspheres had a lower initial burst and a slightly prolonged duration of release than those porous microspheres. In vivo release kinetics of the low burst microspheres were determined by measuring LNG plasma levels after a single intramuscular injection to female rats. At a LNG dose of 41.1 mg/kg, average plasma LNG levels were 6-10 ng/ml in the first 24 h and subsequently remained above 1 ng/ml until 126 days. The duration above the minimum effective LNG plasma level of 0.2 ng/ml was 168 days. By comparison, a similar dose of LNG microcrystals used as control produced a much higher plasma level of 15-21 ng/ml in the first day followed by a fast and continuous decline of LNG levels with a duration of only about 35 days.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Pharmaceutics - Volume 301, Issues 1–2, 14 September 2005, Pages 217-225
نویسندگان
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