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OBJECTIVE:To study the absorption features of Silymarin enteric coated-polyllactic-co-glycolic acid (PLGA) nanoparticles in rat in situ intestine perfusion model and colonic adenoma Caco-2 cell model. METHODS:HPLC method was used to determine the content of silymarin. The absorption rate constant(Ka)and apparent absorption coefficient(Kapp)of Silymarin sus-pension,Silymarin PLGA nanoparticles and Silymarin enteric coated-PLGA nanoparticles were investigated in duodenum,jejunum, ileum and colon of rat in situ intestine perfusion model;the apparent permeability coefficient (Papp) of those drugs containing low-concentration,medium-concentration and high-concentration(20,40,60 μg/mL)of silymarin in Caco-2 cell model were also investigated. RESULTS:Compared with Silymarin suspension,Ka and Kapp of Silymarin PLGA nanoparticles and Silymarin enteric coated-PLGA nanoparticles were all increased in duodenum,jejunum,ileum and colon(P0.05). CONCLUSIONS:Silymarin enteric coated-PLGA nanoparticles can effectively increase the intestinal ab-sorption,cellular uptake and transmembrane transport rate of silymarin.
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Objective To detect the recombinant intermediates of hepatitis B virus (HBV) between genotype B and C in vitro. Methods Vector Plenti6/V5-D-topo-X was genetically modified by genotype B and C to transfect HepG2 cells. Then the HepG2 cells were amplified and sequence of the nucleic acid after the transinfection was tested and compared with RDP3Beta40 software package and bootscanning procedure in SimPlot program package. Results Three recombinant intermediates of HBV between genotype B and C were identified in vitro. Genotype C in the precore region plus the core gene spanning nucleotide positions from 1740-1838 to 2443-2485 contributed to the recombination with genotype B. Isolate R1 recombinant intermediate had 2 break points at nt2170-2172 and nt2188-2189. Nucleic acid changed from CAC to TGT and from GA to AC, respectively. Isolate R2 recombinant intermediate had a break point at nt1740-1 838, and 3 bases changed in different nucleic acid sites: from A to T at nt1740, from C to T at nt1753, and from G to A at nt1838, respectively. Isolate R3 recombinant intermediate had a break point at nt2443-2483, and 4 bases changed in different nucleic acid sites: from C to T at nt2443, from A to G at nt2452, from T to C at nt2480, and from C to T at nt2483, respectively. Conclusion The recombinant intermediates of HBV between genotype B and C have been detected in vitro and the changes have been identified in the precore region plus the core gene in genotype B and C.
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Objective To prepare thermosensitive in situ gel of ibuprofen ( IBU) inclusion complex with poloxamer and evaluate its release behavior in vitro and in vivo. Methods The IBU inclusion complexes were prepared by lyopyilization. The poloxamer 407 and 188 were added as a base for the preparation of gel. The release of inclusion complex gel was evaluated by membraneless models. The pharmacokinetics was evaluated after intramuscular injecting IBU solution or IBU inclusion complex gel to New Zealand white rabbits. The drug concentrations in the plasma were measured by HPLC. Results The loading amount of IBU was 10. 24% . The corrosion of gel and the release of IBU correspond to zero-order kinetics. Compared with IBU solution,the tmax and t1/2 were prolonged and Cmax was degraded while AUC was enhanced obviously. Conclusion The IBU inclusion complex gel is used as a good injection with sustained-release which can improve the analgesia and an- ti-inflammatory effect of ibuprofen. And our study builds up the foundation for the use of water-insoluble drug in thermosensitive in situ gel.
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Objective To investigate the effects of different technical conditions on the microvesicle size,envelopment rate,morphology of surface and so on in order to select the best technical conditions to prepare HCPT(10-hydroxy-camptothecin)-loaded PLGA microvesicles.Methods Microvesicles were prepared by a water/oil/water emulsion and solvent evaporation method.Various factors related to the envelopment rate and micmparticle size were studied,such as the ratio of water phase and oil phase,ultrasound power,and time,stirring time and so on.Single factor experiments and orthogonal design testing was carried out to optimize the technology of microvesicles preparation.Results The best processing conditions for microvesicles preparation were as following: HCPT 25 mg,PLGA 1.875 g,the ratio of internal and external phases 1∶15,and the PVA concentration 3%.These preparative variables produced global,smooth and glossy microvesicles.Electric charges were probably between-40 to 0 mV,microvesicles sizes ranged from 500 to 1 000 nm,envelopment rate was 79.33%,drug loading to the microvesicles was 0.478 3%,and ultrasonic imaging was clear in vitro.Conclusion Our optimize technical conditions can prepare injectable microvesicles by ultrasound.
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Objective To investigate the release feature of dexamethasone sodium phosphate from thermosensitive in situ gels in vitro. Methods Rotation rheometer was used to measure the changes of viscosity with temperature. The membraneless model was applied in assessing corrosion behavior of gel using a thermostatic shaker (50 r/min) at an amplitude of 2.5 cm, taking phosphate buffered solution (pH 7.2) as releasing media. The release behavior was investigated by HPLC on a C18 reverse column DiamonsilTM (250 mm?4.6 mm, 5 ?m). The mobile phase consisted of triethylamine solution-methanol-acetonitrile (38∶28∶34), pumped at 1.0 ml/min, and the detection wavelength was set at 242 nm. Results When the temperature was near to the sol-gel transition temperature, the viscosity rose suddenly. Taking dexamethasone sodium phosphate (2 ml, pH 7.2) as media, the gel dissolution and drug release rate followed the zero order kinetics, and the cumulative gel dissolution (Q1) and cumulative drug release (Q2) equations were Q1=0.8238t (r=0.999, P
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Objective To investigate the effect of total saponins of panax notoginseng(PNS)on the production of collagen Ⅰ,Ⅲ and TGF-?1 in rats with experimental fibrosis.Methods Experimental fibrosis model was copied by intracutaneous injection of BSA and rats feeding on diet rich in lipid.From the 1st day after BSA injection,SPN(60 or 30 mg/kg)or Colchicine were given intracutaneously once a day for 42 days.All animals were sacrificed on the 43rd day.Their hepatic function was evaluated by determining the levels of ALT,AST,ALB in serum.The progression of hepatic fibrosis was confirmed by pathological analysis.Then type collagenⅠ,Ⅲ and TGF-?1 were observed with immunohistochemical method.Results The BSA injection significantly elevated the levels of ALT and AST,while SPN treatment significantly down-regulated them.But the level of ALB was opposite to that of ALT or AST in SPN treatment group.The positive staining of the collagenⅠ,Ⅲ and TGF-?1 was stronger in hepatic fibrosis model group than in SPN treatment group.The contents of the collagen were identical to the immunohistochemical results.Conclusion SPN has the protective effect against liver fibrosis.
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Objective To investigate the relative molecular weight of polysaccharides in Bletilla striata by matrix-assisted laser desorption ionizatior/time-of-flight mass (MALDI-TOF-MS). Methods 2, 5-Dihydroxybenzoic acid (DHB) as a matrix was used. By drop drying at room temperature the proportion of the matrix and polysaccharide sample was 1.5∶1. Baseline mode and laser intensity at 1 500-2 500 units were carried out. Results The relative molecular weights of polysaccharides in B. striata were 6?104-3?105, whose distribution rang was wide. Conclusion The relative molecular weights of polysaccharides in B. striata are obtained by MALDI-TOF-MS technique in the proportion of DHB-polysaccharides in B. striata 1.5∶1, which is valuable for the preparation and good quality by the direct drop drying method.
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Objective: To make out effects of different absorbents, mositure and alcohol amount on the absorption of lipophilic extract of Rhizoma Alismatis in Jinzhe Guanxin Capsules in order to solve its preparation procedure problem. Methods: The absorbent activity and absorbed dose were determined. Results: The moisture of lipophilic extract of Rhizoma Alismatis was lower than 25%, 95% alcohol amount for every gram was 0.25～ 0.5 ml when aluminum hydroxide gel was used as an absorbent. This was the best procedure condition.Conclusion: Jinzhe Guanxin Capsule preparad by aluminum hydroxide gel conforms with the preparation quality requirement.