RESUMO
Objective:To determine the equilibrium solubility and the apparent oil/water partition coefficients of nicotinate-curcu-min ester,so as to provide basis for the new formula design. Methods:Nicotinate-curcumin ester was dissolved in buffer solution with pH of 1.2-7.8. HPLC was used to detect the equilibrium solubility of nicotinate-curcumin ester in various solutions. The apparent oil/water partition coefficients in octanol-water and octanol-buffer solution system were measured by a shaking-flask method. Results:The solubility of nicotinate-curcumin ester in pH 6.8 was the highest. The apparent oil-water partition coefficients of nicotinate-curcumin ester in pH 1.2,5.8,6.5 and 7.8 were lgPapvalues within the range(lgPap=1.69-1.98) beneficial to the absorption in vivo. But in pH 2,5 and 6.8,the lgPapvalues were greater than 2 with strong lipophilicity. Conclusion:The equilibrium solubility as well as ap-parent oil/water partition coefficients of nicotinate-curcumin ester is greatly influenced by the pH value of media. In the pH value with relatively high solubility,lipophilicity is stronger,suggesting it is difficult to be absorbed by the body and needs to be further studied on dosage forms.
RESUMO
Objective: To provide basis for the preparation process study by establishing an HPLC determination method for nicotinate-curcumin ester.Methods: A C18 column(250 mm×4.6 mm,5 μm) was used at 30℃ with the mobile phase of acetonitrile-0.5% acetic acid glacial(65∶35) at a flow rate of 1.0 ml·min-1.The UV detection wavelength was 280 nm.Results: The good linear relationship of nicotinate-curcumin ester was shown within the range of 5.200-104.000 μg · ml-1(r=0.9999 4), The average recovery of nicotinate-curcumin ester and its nanoparticles was 100.1% and 100.9%with RSD of 1.260% and 0.995 0%(n=6), respectively.Conclusion: The method is convenient, accurate and reproducible, and suitable for the determination of nicotinate-curcumin ester nanoparticles and the studies on the preparation technology.