2002 Fiscal Year Final Research Report Summary
Preparation of polymer microcapsules enclosing active agent with controlled-release property
| Project/Area Number |
13555215
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
反応・分離工学
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
KITAMURA Yoshiro Okayama University, Department of Environmental Science & Technology, Professor, 環境理工学部, 教授 (90032945)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIZAWA Hidekazu Okayama University, Department of Environmental Science & Technology, Associate Professor, 環境理工学部, 助教授 (20244262)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Drug delivery system / Polymer microcapsule / Microparticulate dosage form / Controlled release / Solvent evaporation method / Polylactide / Initial burst / Interaction |
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| Research Abstract |
This research was conducted to clarify the effect of process parameters which affected the release properties of microparticulate drugs encapsulating bioactive materials by solvent evaporation method via O/O emulsion preparation.
At first, the experiment was carried out in the case that microparticle drug was dispersed in oil droplets, in the solvent evaporation method to prepare biodegradable polymer microcapsules. The diameter of polylactic acid microcapsules was constant to be ca. 50μm in spite that the loading amount of microparticle drug was varied in a wide range. whereas, the diameter of polylactic acid microcapsules increased in an increase in polymer concentration dissolved in dispersed oil droplets and in a decrease in stirring rate in solvent evaporation. From the release experiment in which preparation conditions, such as diameter of polylactic acid microcapsules and loading amount of drug, were varied, we successfully construct the release model, namely core-shell model, which well described the degree of initial burst and the release rate after initial burst.
Secondly, we tried to clarify the effect of process parameter on release properties in the case of polylactic acid microcapsules enclosing drugs which had an interaction between drug and polymer. The prepared polylactic acid microcapsules showed many creases in their surface. The crease became more at higher drug content in polymer microcapsules. It was appropriate to consider that the crease on the microcapsule led the initial burst because the initial burst increase in an increase in drug content in polymer microcapsules. That is, the surface area increased due to crease on surface. This fact gave a warning about the interaction between drug and polymer in preparation of microparticulate drug enclosing a new drug.
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