The effects of nicorandil ( NICO ) on the contractility, automati -city, excitability, functional refractory period ( FRP ) & dose-response curves for isoprenaline as well as calcium were studied in guinea pig papillary muscles. NICO could decrease the amplitude of contraction of papillary muscles dose-dependently. Propranolol and NICO might antagonize the inotropic effect of isoprenallne. Verapamil & NICO induced Ca2+ antagonistic effects in a non-competitive manner, & the maximal Ca2+ response of papillary muscles decreased signifi- cantly. The automaticity of papillary muscles was decreased Significantly when the concentration of NICO reached 1.4 mmol/L, but exerted no effect on their excitability & the functional refractory period.

OBJECTIVE:To optimize the preparation techniques for floxuridinyl diacetate solid lipid nanoparticles(FUDRA-SLN).METHODS:The FUDRA-SLN was prepared by film-ultrasound dispersion method with soybean phos?pholipids as carrier,and the preparation techniques were optimized by means of an orthogonal test design with entrapment ef?ficiency and appearance as indexes of investigation.RESULTS:The FUDRA-SLN prepared in the optimized techniques was even and regular in appearances,with particle diameter at(215?83)nm,entrapment efficiency at98.27%and drug loading dosage at8.20%.CONCLUSIONS:FUDRA-SLN prepared by the optimized film-ultrasound dispersion method has a high entrapment efficiency and high drug loading dosage,and this method is suitable for the laboratory preparation.

OBJECTIVE: To establish RP-HPLC method for the fast determination of floxuridinein in serum and homogenate of some of the organs of mice. METHODS: The determination was performed on C18 chromatographic column with its mobile phase consisted of phosphate buffer(pH= 7.4) - methanol(95∶5) and with its detection wavelength at 268nm. RESULTS: Linear detection concentration ranges of floxuridinein were all at 15～240?g/ml. The minimum detection concentration was 3?g/mL(S/N≥3). The average extraction recovery was above 95%. The average recovery ranged from 91%to 112%. Both the intra-day and inter-day precisions were less than 10%. CONCLUSION: The method is simple, rapid, reliable and economical, and it can be used for the determination of serum floxuridinein concentration and the study of its body distribution in animals.