ABSTRACT
OBJECTIVE:To prepare Diacerein (DCR)-loaded (poly lactic-co-glycolic acid) PLGA microspheres for intra-articular injection and investigate its related properties. METHODS:PLGA was used as microspheres material,and the microsphere was prepared by emulsification solvent evaporation method. The contents of DCR-PLGA microspheres were determined by HPLC,and drug-loading amount and entrapment efficiency were also calculated. Using entrapment efficiency as evaluation index,the preparation technology was optimized by orthogonal test. The morphology and particle size of microspheres were observed by optical microscope and SEM. Accumulative release rate was investigated by using in vitro release test. RESULTS:The linear range of DCR was 2.1-105.0 μg/mL(r＝0.999 9). RSDs of precision,stability,reproducibility and recovery tests were all lower than 2.0%. The optimal technology was PLGA concentration of 200 mg/mL,volume ratio of oil-water 1∶50,polyvinyl alcohol concentration of 1%. The prepared DCR-PLGA microspheres were spherical,average particle size was(11.2±4.7)μm, drug-loading amount was(4.25 ± 0.26)% and encapsulation rate was(92.30 ± 1.93)%,respectively. The drug release rate of DCR-PLGA microspheres within 360 h was about(73.08 ± 5.33)%. CONCLUSIONS:DCR-PLGA microspheres are prepared successfully with good morphology,suitable particle size and obvious sustained release effect,which are suitable for intra-articular injection.
ABSTRACT
Objective To determine the solubility of rhein in different vehicles and its partition coefficients in the n-octanol-water system for designing new formulations. Methods High performance liquid chromatography(HPLC) method was established to determine the concentration of rhein in water,different pH solutions and different solvents;the partition coefficients for the n-octanol- buffer solution systems were determined by shaking flask method. Results The equilibrium solubility of Rhein was 3.89 μg·mL-1and the lgP was 2.79 in water at 37 ℃.The solubility of rhein was increased with the raise of pH, which could reach 362.20 and 431.65 μg·mL-1in phosphate buffer solution at pH 6.8 and 7.4,respectively.Solubility of rhein in the semi polar solvent was relatively good,which can up to 2 971.74 μg·mL-1in PEG400.The oil-water partition coefficients of rhein were decreased with the increase of pH,and were 0.83 and 0.54 in phosphate buffer solution at pH 6.8 and 7.4,respectively. Conclusion Rhein is almost not soluble in water.With the raise of pH,the solubility is increased but the oil-water partition coefficient is decreased.
ABSTRACT
OBJECTIVE:To study the targeting of folic acid(FA)-modified docetaxel(DOC)nano-liposome(L-DOC-FA)to hepatocellular carcinoma Bel-7402 cells in vivo and in vitro. METHODS:The cell viability and survival rate of Bel-7402 cells was tested by CCK-8 kit after treated with 0,1,2,5,10 and 20 μg/ml DOC,L-DOC and L-DOC-FA for 24 h. And then,the fluores-cein isothiocyanate was used to label L-DOC and L-DOC-FA nano-liposome,and the rate of L-DOC and L-DOC-FA absorbed by hepatocellular carcinoma Bel-7402 cells were detected. 125I was used to label L-DOC and L-DOC-FA nano-liposome,and then the contents of them in the subcutaneous tumor tissues were detected. 28 Balb/c naked mice were selected and given liver cell suspen-sion via back ih to induce tumor model. After modeling,naked mice were divided into blank control group(normal saline),DOC group(3 mg/kg),L-DOC(3 mg/kg,by DOC)and L-DOC-FA(3 mg/kg,by DOC). They were given relevant medicine intrave-nously once a day for consecutive 30 d. The relative tumor volume in naked mice was detected. RESULTS:DOC,L-DOC and L-DOC-FA all inhibited the cell viability of Bel-7402 cells,the survival rate of cells decreased in concentration-dependant manner;compared with DOC and L-DOC,the cell viability decreased after treated with L-DOC-FA,the survival rate of cells decreased (PL-DOC (31.2%),with statistical significance (P<0.01). The content of L-DOC-FA in tumor was significantly more than that of L-DOC (P<0.01). In addition,3 mg/kg L-DOC-FA showed better inhibitory effect than 3 mg/kg L-DOC and DOC on tumor,and the rela-tive tumor volume was smaller(P<0.01). CONCLUSIONS:L-DOC-FA has obvious targeting to Bel-7402 cells in vivo and in vi-tro,and shows good inhibitory effect on tumor in vivo and in vitro.