Objective To study the uptaking characteristics of puerarin in Caco-2 model system. Methods The transepithelial transporting character of puerarin across Caco-2 cells was investigated by changing the concentration, temperature of drug and using appropriate inhibitors. Results The transport of puerarin across Caco-2 cell monolayers was directional. With the increase of the concentration of pue-rarin, the permeability direction ratio (PDR) was decreased from 2.1 to 1.4. With the increase of temperature, PDR was increased. When the metabolic inhibitors, KCN and 2,4-dinitrophenol, were added, the PDR was decreased from 1.7 to 1.0 and 1.2, respectively. When 100 mg/L Verapamil was added, the permeability coefficient of apical to basolateral was increased from (0.84?0.18)?10-7 cm/s to (1.01?0.17)?10-7 cm/s, and the permeability coefficient of basolateral to apical was decreased from (1.43?0.18)?10-7 cm/s to (1.11?0.24)?10-7 cm/s. Conclusion The evacuation by P-glycoprotein affects the puerarin transepithelial transport across Caco-2 cells.

AIM: In order to prepare the self-microemulsifying soft capsule(SMESC)of pueraria lobata isoflavone and investigate its dissolution property. METHODS: Through solubility experiment,self-microemulsification in vitro,phase diagram and the stability of solution,the optimum formulation was selected for pueraria lobata isoflavone.The dissolution of SMESC was measured taking the commercial tablet as reference. RESULTS: In the selected formulation,Tween-80,1,2-Propanediol and ethyl oleate were screened as emulsifier,co-emulsifier and oil phase,respectively.The optimized proportion was 65∶20∶15 .The dissolution of SMESC in the condition of distilled water,pH6.8 phosphate buffer and 0.1 mol/L HCl were more than 90% in 10 min,while those of the commercial tablet were less than 40% in 90 min. CONCLUSION:In comparison with the commercial tablet,the dissolution of pueraria lobata isoflavone is sufficiently improved at various conditions.

OBJECTIVE:To study the relationship between various composition factors and the dissolution rates of the soft gelatin capsule shell.METHOD:The gelatin disk and gelatin shaped mass method were used by the current CP rotating-basket dissolution apparatus.The effects of shell compositions on the capsule shell dissolution rate were illustrated and discussed.RESULTS:With the increase in the ratio of gelatin glycerol in soft gelatin shell,the dissolution rate of the shell changed irregularly.After storage of 21 days at 40℃，the dissolution rate of the shell decreased at different extent.The dissolution rate of the shaped gelatin mass increased slightly by adding some polymers (pvp,starch).CONCLUSION:Am investigation of these factors and their influence on dissolution may be of assistance in the formulation of soft gelatin capsule shells for various purposes,THE SOFT gelatin capsules should be stored at relatively low temperature.

AIM　To study the release mechanism of fenoprofen calcium (FC) from hydroxypropylmethylcellulose (HPMC) matrices. METHODS　The release of FC and the erosion properties of hydrophillic matrices containing HPMC was examined at different paddle speed. The release mechanism of FC was further confirmed by evaluating the n value in Peppas equation. RESULTS　The results indicate that the release of FC and the erosion of matrices exhibit zero order kinetic equation, and it exhibits line relationship between them. CONCLUSION　In the first 40 min, FC mainly released by diffusion and erosion from HPMC matrix, while it was controlled by the rate of tablet erosion after 50 min.

In this paper, chloramphenicol was selected as a model drug to prepare in situ gels. The intrinsic dissolution rate of chloramphenicol from in situ gel was evaluated using the surface dissolution imaging system. The results indicated that intrinsic dissolution rate of chloramphenicol thermosensitive in situ gel decreased significantly when the poloxamer concentration increased. The addition of the thickener reduced the intrinsic dissolution rate of chloramphenicol thermosensitive gel, wherein carbomer had the most impact. Different dilution ratios of simulated tear fluid greatly affected gel temperature, and had little influence on the intrinsic dissolution rate of chloramphenicol from the thermosensitive in situ gel. The pH of simulated tear fluid had little influence on the intrinsic dissolution rate of chloramphenicol thermosensitive in situ gel. For the pH sensitive in situ gel, the dissolution rates of chloramphenicol in weak acidic and neutral simulated tear fluids were slower than that in weak alkaline simulated tear fluid. In conclusion, the intrinsic dissolution of chloramphenicol from in situ gel was dependent on formulation and physiological factors. With advantages of small volume sample required and rapid detection, the UV imaging method can be an efficient tool for the evaluation of drug release characteristics of ophthalmic in situ gel.

Oral hydroxycamptothecin nanosuspension (HCPT-Nano) with high supersaturated dissolution level, high permeation and well physical stability, was manufactured by microprecipitation-high press homogenization method. Its pharmaceutical properties were investigated, such as size and distribution, zeta potential, particle shape, physical existence condition, supersaturated dissolution level and so on. Particle size was measured by laser diffraction, and the mean diameters before and after lyophilization were 138 +/- 11.72 nm and 175 +/- 12.74 nm, respectively, for HCPT-Nano. Zeta potentials of HCPT-Nano was over -20 mV. The nanoparticles, being observed by transmission electron microscopy (TEM), were claviform or column in shape. DSC and X-ray diffraction revealed that HCPT existed in the form of crystal for HCPT-Nano. And HCPT-Nano could maintain higher supersaturated dissolution level for long time. So it supplied the possibility of improving oral bioavailability of HCPT when combining together admoveatur of P-gp inhibitor, CsA.

Drug stability is closely related to drug safety and needs to be considered in the process of drug production, package and storage. To investigate the stability of epalrestat, a carboxylic acid derivative, a reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed in this study and applied to analyzing the degradation kinetics of epalrestat in aqueous solutions in various conditions, such as dif-ferent pH, temperatures, ionic strengths, oxidation and irradiation. The calibration curve was A=1.6 × 105C–1.3 × 103 (r=0.999) with the liner range of 0.5–24 μg/mL, the intra-day and inter-day precision was less than 2.0%, as was the repeatibility. The average accuracy for different concentrations was more than 98.5%, indicating that perfect recoveries were achieved. Degradation kinetic parameters such as degradation rate constants (k), activation energy (Ea) and shelf life (t0.9) under different conditions were calculated and discussed. The results indicated that the degradation behavior of epalrestat was pH-dependent and the stability of epalrestat decreased with the rised irradiation and ionic strength;however, it was more stable in neutral and alkaline conditions as well as lower temperatures. The results showed that the degradation kinetics of epalrestat followed first-order reaction kinetics. Furthermore, the degradation products of epalrestat under stress conditions were identified by UHPLC-PDA-MS/MS, with seven degradation products being detected and four of them being tentatively identified.

OBJECTIVETo study on pharmacokinetics of hydroxycamptothecine (HCPT) nanosuspensions in rats after oral administration.

METHODThe plasma concentrations of HCPT were determined by HPLC-FD. The analysis was performed on a diamonsil C18 column (4.6 mm x 200 mm, 5 microm) with 0.3% acetic acid-triethylamine buffer (pH 5.0) and methanol (57: 43) as mobile phase. The flow rate was 1.0 mL x min(-1); the excitation wave was set at 363 nm, and emission wave was set at 550 nm; the temperature was 35 degrees C. All data of concentration-time of HCPT were treated with pharmacokinetics program DAS 2.0.

RESULTThe concentration-peak area of this assay had a good linear relation in the range from 1 to 50 microg x L(-1), and the minimum limit of quantitation was 1 microg x L(-1). The inter- and intra-day precisions of HCPT were smaller than 4.3%, and the accuracy were between -5.59% and 5.59%. The recoveries of HCPT in three plasma concentrations including high, medial, low concentration were 98.94%, 95.88% and 102.69%, respectively, which was in line with the request of biopharmaceutical analysis. The plasma concentration time profiles of HCPT fitted in two-compartment models well, and the main pharmacokinetic parameters found for HCPT after oral administration were as follows: Cmax 13.10 microg x L(-1), Tmax 0.75 h, t(1/2alpha) 8.242 h, t(1/2beta) 136.122 h, AUC(0-t) 116.77 microg x h x L(-1), AUC(0-infinity) 161.93 microg x h x L(-1).

CONCLUSIONThe HPLC-FD method was simple, with good specificity, reproducibility, and could be used to investigate the pharmacokinetics and determinate the concentration of hydroxycamptothecin. The nanosuspension in this study could accelerate the oral absorption rate of HCPT, and make improving bioavailability of HCPT possible.

ATP-Binding Cassette, Sub-Family B, Member 1 ; antagonists & inhibitors ; Administration, Oral ; Animals ; Calibration ; Camptothecin ; administration & dosage ; analogs & derivatives ; chemistry ; pharmacokinetics ; pharmacology ; Linear Models ; Male ; Nanostructures ; Rats ; Rats, Wistar ; Suspensions

Cancer immunotherapy has become a new generation of anti-tumor treatment, but its indications still focus on several types of tumors that are sensitive to the immune system. Therefore, effective strategies that can expand its indications and enhance its efficiency become the key element for the further development of cancer immunotherapy. Natural products are reported to have this effect on cancer immunotherapy, including cancer vaccines, immune-check points inhibitors, and adoptive immune-cells therapy. And the mechanism of that is mainly attributed to the remodeling of the tumor-immunosuppressive microenvironment, which is the key factor that assists tumor to avoid the recognition and attack from immune system and cancer immunotherapy. Therefore, this review summarizes and concludes the natural products that reportedly improve cancer immunotherapy and investigates the mechanism. And we found that saponins, polysaccharides, and flavonoids are mainly three categories of natural products, which reflected significant effects combined with cancer immunotherapy through reversing the tumor-immunosuppressive microenvironment. Besides, this review also collected the studies about nano-technology used to improve the disadvantages of natural products. All of these studies showed the great potential of natural products in cancer immunotherapy.

A commercial albumin-bound paclitaxel nano-formulation has been considered a gold standard against breast cancer. However, its application still restricted unfavorable pharmacokinetics and the immunogenicity of exogenous albumin carrier. Herein, we report an albumin-bound tumor redox-responsive paclitaxel prodrugs nano-delivery strategy. Using diverse linkages (thioether bond and disulfide bond), paclitaxel (PTX) was conjugated with an albumin-binding maleimide (MAL) functional group. These pure PTX prodrugs could self-assemble to form uniform and spherical nanoparticles (NPs) in aqueous solution without any excipients. By immediately binding to blood circulating albumin after intravenous administration, NPs are rapidly disintegrated into small prodrug/albumin nanoaggregates