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OBJECTIVE：To prepare and characterize glycyrrhetinic acid （GA）nanoparticles，and to evaluate its in vitro anti-tumor activity. METHODS ：Using PVP K 30 as carrier ，GA nanoparticles were prepared by anti-solvent precipitation and freeze-drying method. X-ray diffraction ，infrared spectrum ，differential scanning calorimetry and granularity analysis were used to characterize the nanoparticles ；HPLC method was used to measure the solubility and drug-loading amount of GA in the nanoparticles. MTT method was used to assay the in vitro inhibition activity of GA raw material and nanoparticles （GA doses were 12.5，25，50，100，200 μmol/L）on human liver cancer cell HepG 2 and calculate its IC 50. RESULTS ：The characteristic peaks of X-ray diffraction and infrared absorption of GA disappeared in the nanoparticles and the endothermic peak changed. The particle size of the nanoparticles was （194.88±23.52）nm，which was lower than （2 592.33±207.51）nm of raw material. The dispersion index was 0.24±0.04，which was higher than 0.15±0.03 of raw material. The average drug-loading amount of GA was 15.99％. Moreover，the solubility of nanoparticles increased from （1.05±0.01）μg/mL to（250.00±0.15）μg/mL. The results of antitumor test in vitro showed that the cell survival rates in the group of GA raw material 200 μmol/L and GA nanoparticles groups were significantly lower than that in blank control group ，and the cell survival rates of GA nanoparticles groups （except for 12.5 μmol/L group）were significantly lower than that of same dose group of raw material （P＜0.01）. IC 50 of GA nanoparticles was 86.3 μmol/L，which was lower than 364.4 μmol/L of raw material. CONCLUSIONS：GA nanoparticles are prepared successfully ；the prepared nanoparticles have small size and uniform distribution ，and the solubility are increased and antitumor activity in vitro are enhanced.
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Objective According to the clinical medicinal crystal form———form γ of levonorgestrel, to establish the quantitative analysis method for levonorgestrel form γ by powder X-ray diffraction (PXRD) . Methods Firstly, single crystal X-ray diffractometry and powder X-ray diffractometry were used to confirm that the prepared levonorgestrel form γ was 100％ polymorphic purity, which provided a standard sample for quantitative analysis by single peak method; then, the standard samples of different quality levonorgestrel form γ for powder X-ray diffraction were weighed, the peak intensity values of characteristic diffraction peaks d = 6.4 , d = 6. 1 and d = 5. 6 of form γ as quantitative parameters selected, a linear relationship between the peak intensity value and the quality of form γ was established; finally, the content of levonorgestrel form γ was quantitatively analyzed. Results The peak intensity values of characteristic diffraction peaks d = 6.4 , d = 6.1 and d = 5.6 of levonorgestrel form γ and the quality showed a good linear relationship.In the range of form γ masses of 5 mg to 50 mg, the regression linear equations wereY = 459.59X+5 536.5, R2 = 0.993 0, Y = 430.03X+6 867.6, R2 = 0.990 5,Y = 615.95X+ 6 209.5, R2 = 0.990 8,respectively. Conclusion The method is simple, rapid, accurate and reliable, it can be used as quality control method for levonorgestrel polymorphs.
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Objective To study the gastrointestinal absorption process of three letrozole polymorphs in rats, and evaluate the different pharmacokinetics parameters of different polymorphs. Methods A total of 18 SD rats were given the different letrozole polymorphs. Then the high-performance liquid chromatographic method was used for the determination of plasma concentration of letrozole in these SD rats.Finally the pharmacokinetic parameters among the different polymorphs were calculated. Results Cmax of letrozole crystal form I, crystal form II and crystal form III were (9.247± 4.612) ,(23.387± 9.049) and (15.682±1.589) mg·L-1, respectively, and AUC0→t were(198.115±47.014) ,(476.641±125.467) and (271.817±41.068) mg·L-1·h,respectively. Conclusion The different crystal forms of letrozole result in different plasma concentration in SD rats. Crystal form II may be its preponderant polymorphs which deserves further research and development.
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Objective Two co-crystals of isonicotinic acid hydrazide(INH)-malonic acid and INH-glutaric acid were prepared.The formation mechanism and intermolecular interaction were studied. Methods Three-dimensional structure of 2 co-crystals were obtained though single crystal X-ray diffraction(SXRD), and intermolecular interaction was analyzed using Hirshfeld surface method. Results INH-malonic acid crystalized in stoichiometric ratio of 1:0.5,while INH-glutaric acid in 1:1.Two co-crystals maintain their stable arrangement in space by hydrogen bond and van der Waals force. Conclusion With the existence of pyridine ring and carbohydrazide group in INH,which mainter-molecular interaction in co-crystal can be directly and clearly revealed by Hirshfeld surface analysis.
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This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.
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The powder X-ray diffraction Fourier fingerprint pattern technique was used to develop a new quantitation method for the analysis of andrographolide and dehydroandrographolide. And the high performance liquid chromatography method was used to evaluate the quantity of andrographolide and dehydroandrographolide. The relationship of diffraction peak intensity and content of andrographolide and dehydroandrographolide was investigated. The powder X-ray diffraction Fourier fingerprint pattern analysis technique can be used to evaluate the quantity of andrographolide and dehydroandrographolide in the herb simultaneously.
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<p><b>OBJECTIVE</b>To develop an identitication and quantitation method for Radix Salviae Miltiorrhizae.</p><p><b>METHOD</b>The powder X-ray Diffraction Fourier Fingerprint Pattern technique was used for this purpose. The high performance liquid chromatography method was used to evaluate the quantity of Tanshinone II A in 9 samples and 1 drug reference substance. The relationship of diffraction peak intensity and content of Tanshinone II A was investigated.</p><p><b>RESULT AND CONCLUSION</b>The powder X-ray diffraction Fourier Fingerprint Pattern analysis technique can be used to identify Radix Salviae Miltiorrhizae and to evaluate the quantity of Tanshinone II A in the drug at the same time.</p>