pH/enzyme dual sensitive Gegenqinlian pellets coated with Bletilla striata polysaccharide membranes for the treatment of ulcerative colitis.

Gegen Qinlian Decoction, derived from Zhang Zhongjing's Treatise on Typhoid Fever, has been widely used in the treatment of various common diseases, frequently-occurring diseases and difficult and complicated diseases, such as ulcerative colitis. In this study, Bletilla striata polysaccharide (BSP) was innovatively used as a film coating material to prepare Gegen Qinlian pellets with dual sensitivity of pH enzyme for the treatment of ulcerative colitis. BSP has the ability to repair the inflamed colon mucosa and can produce synergistic effects, while avoiding the adverse therapeutic effects caused by the early release of drugs from a single pH-sensitive pellets in the small intestine. The prepared pellets have a uniform particle size, good roundness, a particle size range from 0.8 mm to 1.0 mm, and a particle yield is 85.6 %. The results of in vitro release showed that ES-BSP pellets hardly released drugs in the pH range of 1.2-6.8. However, in the colon mimic fluid containing specific enzymes, the drug release was significantly accelerated, demonstrating the sensitivity of the pellets to pH enzymes. In vivo and ex vivo fluorescence imaging of small animals showed that Gegen Qinlian pellets with dual sensitivity of pH enzyme remained longer in the colon compared with pH-sensitive pellets. In vivo pharmacodynamics study showed that the Gegen Qinlian pellets with dual sensitivity of pH enzyme had a better therapeutic effect in the rat model of the ulcerative colon than the commercially available Gegenqinlian pellets in the control group.

Transdermal Administration of Ibuprofen-Loaded Gel: Preparation, Pharmacokinetic Profile, and Tissue Distribution.

The purpose of this study was to compare the pharmacokinetics and tissue distribution of ibuprofen (IBU) gel in female rats after transdermal administration through the skin of the abdomen and back. IBU was used as the model drug to prepare carbomer gel. After the abdominal and back administration, the concentration of IBU in rat plasma was detected by high-performance liquid chromatography (HPLC). Besides, the contents of IBU in the uterus, heart, liver, spleen, lung, and kidney were detected, respectively, to clarify the distribution characteristics in vivo. Through abdominal route, the AUC0- ∞ (area under the concentration-time curve from time zero to infinity) of uterus was 424.75 µg/g h, which is 3.60 times higher than that of plasma, and was significantly higher than that of other tissues (P < 0.0001). Tmax (peak time) of uterus and plasma was 4 h and 2 h, respectively. Upon transdermal application of IBU to the back, the AUC0-∞ of uterus was 75.47 µg/g h, which is 12.63 times lower than that of plasma, while Tmax of uterus and plasma was not lower than 20 h. These results indicated that IBU entered the blood circulation through abdominal administration in a small amount and mainly of the drug entered the uterus, while IBU entered the blood circulation and redistributed to tissues after absorption through the dorsal skin slowly. IBU could effectively reach the uterus and have a certain targeting through abdominal administration, which provides a prospect for clinical transdermal administration in the treatment of dysmenorrhea.

[Mechanism of gambogenic acid in resisting angiogenesis of lung cancer in vitro].

The aim of this paper was to observe the effect of gambogenic acid on angiogenesis of lung cancer and its preliminary mechanism. After culturing lung adenocarcinoma A549 cells, the conditioned medium was treated with gambogenic acid and then used to culture human umbilical vein endothelial cells (HUVECs) to establish the indirect contact cell co-culture system. A two-dimensional culture model of HUVEC was established with matrigel to observe the effect of gambogenic acid on angiogenesis. DAPI staining was used to observe the morphological changes in HUVEC cells after treatment with gambogenic acid under the fluorescence microscope. Annexin V-FITC/PI staining and flow cytometry analysis were used to determine gambogenic acid's effect on HUVEC cell apoptosis rate. The protein expressions of PI3K, p-PI3K, Akt, p-Akt were measured by Western blot. PTEN-siRNA was transfected into cells, and RT-PCR was used to detect the expression levels of PI3K and Akt genes. Gambogenic acid can significantly inhibit angiogenesis, and its inhibitory effect was dose-dependent. DAPI staining showed apoptotic morphological features of HUVEC cells under fluorescence microscope. Annexin V-FITC/PI staining showed that gambogenic acid induced apoptosis in HUVECs. The results of Western blot showed that the expressions of p-PI3K and p-Akt protein were down-regulated with gambogenic acid, while the expressions of PI3K and Akt protein was insignificant. The results of RT-PCR indicated that the expressions of PI3K and Akt protein were up-regulated by PTEN siRNA. Gambogenic acid can inhibit angiogenesis in lung cancer in vitro, and the mechanism of inhibiting angiogenesis may be related to the PI3K/Akt signaling pathway.

[Applicability of a natural swelling matrix as the propellant of osmotic pump tablets].

The purpose of this study is to investigate the applicability of a natural swelling matrix derived from boat-fruited sterculia seed (SMS) as the propellant of osmotic pump tablets. The sugar components, static swelling, water uptake and viscosity of SMS were determined and compared with that of polythylene oxide (WSR-N10 and WSR-303). Both ribavirin and glipizide were used as water-soluble and water-insoluble model drugs. Then, the monolayer osmotic pump tablets of ribavirin and the bilayer osmotic pump tablets of glipizide were prepared using SMS as the osmotically active substance and propellant. SMS was mainly composed of rhamnose, arabinose, xylose and galactose and exhibited relatively high swelling ability. The area of the disintegrated matrix tablet was 20.1 times as that at initial after swelling for 600 s. SMS swelled rapidly and was fully swelled (0.5%) in aqueous solution with relative low viscosity (3.66 +/- 0.03) mPa x s at 25 degrees C. The monolayer osmotic pump tablets of ribavirin and the bilayer osmotic pump tablets of glipizide using SMS as propellant exhibited typical drug release features of osmotic pumps. In conclusion, the swelling matrix derived from boat-fruited sterculia seed, with low viscosity and high swelling, is a potential propellant in the application of osmotic pump tablets.

[Real-time UV imaging of chloramphenicol intrinsic dissolution characteristics from ophthalmic in situ gel].

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.

[Studies on absorption kinetics of paeonol and paeonol-beta-CD in rat's intestines].

To explore the absorption mechanism of paeonol-beta-CD from various intestinal segments and offer biopharmaceutics data for paeonol new dosage form. The absorption kinetics and permeability rate consatants were investigated by the in situ perfusing method in rats. The absorption of the drug conforms to the firt-order kinetics and passive transport mechanism . The results indicate that paeonol-beta-CD absorption mechanism wasn't change.

[Optimization of formulation of Fufang Danshen immediate release tablet by colligation score].

OBJECTIVE: To optimize the formulation of immediate release tablet. METHOD: The immediate release tablet was prepared by using dry granules. The preparation was optimized by using orthogonal design which took the flow property of granules, the hardness, the disintegrating time and the dissolution rate of the tablet as indices. RESULT: The optimized formulation contained 40% microcrystalline cellulose, 10% sodium carboxymethyl starch and 15% dextrin. The hardness disintegrating time and T50 of the tablet were 4.5 kg, 3 min, 5 min respectively. CONCLUSION: It is successful to prepare on immediate release tablet using the optimized formula above.