ABSTRACT
OBJECTIVE: To establish a method for determination of N-methyl-2-pyrrolidone(NMP) in workplace air by solvent desorption-gas chromatography. METHODS: NMP in the workplace air was collected with activated carbon tube and desorbed with methanol ∶dichloromethane(5 ∶95, V/V). After desorption, it was separated by capillary column separation, and detected by flame ionization detector. RESULTS: The good linear concentration of NMP was 0.51-4 108.00 mg/L. The correlation coefficient was 0.999 9. The detection limit was 0.08 mg/L(calculated by 3 times of standard deviation). The average desorption efficiency was 101.68%-103.44%. The within-run and between-run relative standard deviations were 1.94%-3.97% and 0.97%-2.26%, respectively. The sample could be stored at room temperature for at least 14 days. CONCLUSION: The developed method is suitable for the determination of NMP in workplace air.
ABSTRACT
Objective: To evaluate the percutaneous absorption properties of dencichine. Methods: Shaking flask method was used to determine the apparent solubility and oil-water partition coefficient of dencichine. The Franz diffusion cell method was adopted and skin of mice and pig was used as the model skin. The content of dencichine and optimized penetration enhancer were determined using HPLC. Results: Dencichine is water soluble with a low lg P value. Dencichine showed a better penetrability in mice skin than in pig skin. The permeation profiles of dencichine can be fitted well by Higuchi model. The significant percutaneous absorption for dencichine is 5% NMP. Conclusion: Dencichine shows the certain perctaneous absorption ability. And the skin permeation profiles are related with the diffusion rate of the drug in skin. The permeability rate could be promoted by 5% NMP.