RESUMO
OBJECTIVE:To study the change in grain size and in vitro dissolution ratio of Atractylodes macrocephala after ultramicronization. METHODS: The particle size before and after ultramicronization was analyzed using particle size analyzer. The content of the sample was determined by HPLC using atractylenolide Ⅲ and atractylenolide Ⅰ as indexes to reflect the dissolution ratio. RESULTS: After ultramicronization, the particle size of the sample became thinner obviously, about 30% that of the common fine powder, and the content increased by 27% as compared with the common fine powder. CONCLUSION: The ultramicronization can significantly decrease the particle size, increase specific surface area and contribute to the dissolution of atractylenolide Ⅲ and atractylenolide I from Atractylodes macrocephala.