| 초록 |
Valsartan is widely used to control high blood pressure, treat congestive heart failure, and improve survival rates for people who have had a heart attack. Oral bioavailability of valsartan is very low (less than 40%) due to its poor water solubility. In this work, we have improved dissolution rate of valsartan by preparing single particles without excipients. This will help certain takers with pre-existing renal impairment because some organic excipients mixed with valsartan can potentially harm those patients. The fine valsartan particles with mean diameter of 0.1 m were obtained without excessive agglomeration by ASES (Aerosol Solvent Extraction system) using subcritical CO2 in the condition of 70 bar and 5oC. It is found that the particles obtained from the condition of lower temperature were less likely to be agglomerated. It is believed that melting point depression of valsartan took place because CO2 might be included in solid phase of valsartan. It is observed that valsartan began to melt around 40oC in subcritical CO2, differently from that of raw valsartan in air is 100±0.2oC. Therefore, processed valsartan in subcritical CO2 at low temperature improved its dissolution rate because of the small sized and little agglomerated particles. |
