Controlled-release herbicide formulations have been shown to decrease the leaching potential of several herbicides under laboratory and รeld conditions. The utility and efficacy of these formulations may be improved by combining several herbicides and a fertilizer source in a single formulation. The
Controlled Release of Goserelin from Microporous Polyglycolide and Polylactide
โ Scribed by Andrey Kovalchuk; Wilfried Fischer; Matthias Epple
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 305 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1616-5187
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โฆ Synopsis
Abstract
Summary: Two microporous biodegradable polyesters, i.e., PGA and PDLLA, were obtained by solidโstate polymerization reaction from the sodium salts of the corresponding ฮฑโhydroxycarboxylic acids after washing out the byโproduct sodium chloride. The polymers were shaped by cold uniaxial pressing, by hot uniaxial pressing, and by extrusion at elevated temperature. Due to the special microporosity of the polymers, the introduction of drugs is possible at moderate temperature. The release kinetics of the model drug Phe and of the antiโtumor drug goserelin (an LHโRH agonist) from compacted polymer samples were fast (approx. 2 d). The release kinetics of goserelin were corrected for the decomposition of the drug. External coatings with PDLLA or PLLA obtained by immersion in polymer solution strongly slowed down the release kinetics in the case of the PDLLA coating, giving an almost linear release during 100 d. A coating with PLLA was unsuitable to slow down the release kinetics.
SEM picture of the surface of a PDLLAโcoated extruded sample (#9).
magnified imageSEM picture of the surface of a PDLLAโcoated extruded sample (#9).
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