Preparation and release properties of biodegradable chitin microcapsules: I. Preparation of 6-mercaptopurine microcapsules by phase separation methods

F. L. Mi, Y. C. Tseng, C. T. Chen, S. S. Shyu

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1 Citation (Scopus)


Chitin [poly-(N-acetyl-1,4-β-D-glucopyranosamine)] microcapsules were prepared by the simple desolvation and the non-solvent addition phase separation methods. In the simple desolvation method, chitin droplets were dropped into the desolvation agent (water, ethanol, or acetone) and microcapsules soon formed. Several solvent-nonsolvent pairs: N,N-dimethylacetamide (DMAc)water, DMAc-ethanol, DMAc-n-propanol, DMAc-n-butanol, and DMAc-acetone with different solubility parameter difference, (Δδ) were chosen to prepare chitin microcapsules containing 6-mercaptopurine by using the nonsolvent-addition phase separation method. The results showed that the surface morphology and release behaviour of the microcapsules were greatly affected by different solvent-nonsolvent pairs. The surface of the microcapsules prepared from the system of high Δδ was more smooth than those from the systems of low Δδ. The drug content using the simple desolvation method increased with decreasing Δδ because of the higher film formation rate of the microcapsules. On the other hand, the drug content using the nonsolvent addition method was lower than that using the simple desolvation method because of the dispersion forces, applied by mechanical stirring. Microcapsules prepared by the simple desolvation method had a narrower size distribution and larger mean size than those prepared by the nonsolvent addition method.

Original languageEnglish
Pages (from-to)15-25
Number of pages11
JournalJournal of Microencapsulation
Issue number1
Publication statusPublished - Jan 1997
Externally publishedYes



  • Biodegradable
  • Chitin
  • Drug release
  • Mercaptopurine
  • Microcapsule
  • Phase separation

ASJC Scopus subject areas

  • Chemistry (miscellaneous)
  • Pharmaceutical Science
  • Chemical Engineering(all)
  • Pharmacology

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