Preparation of levodopa/carbidopa compound drug resins

The main objective of this study was to prepare the levodopa/carbidopa compound drug resins and investigate affecting factors such as drug concentration, temperature, particle size. The drug resins were made by bath method and the effects of above factors during the process of preparation was studied. Studies on the stabilities of drugs and drug resins were carried out by HPLC. The Results showed that the preparation of drug resins was influenced by drug concentration, resin particle size, reaction temperature and solvent concentration. In certain conditions the degradation peaks were found in the chromatograms of levodopa and carbidopa while the drug-resins remained undegraded. The study indicates that the drug resin technology is an effective way of improving stability of the drug and possesses certain sustained-release effects

preparation of the sustained release metformin hydrochloride microcapsules by the Wurster fluidized bed

The main objective of this study was to prepare sustained release metformin hydrochloride microcapsules by the Wurster fluidized bed and to obtain the optimized coating process and formulation. Fine microcapsules without agglomeration were obtained in a continuous coating process with the atomization air pressure of 0.2Mpa and an appropriate coating speed temperature. With other design variables of coating process fixed, the effects of different fluidizing air volume, coating temperature, coating speed, coating material, coating materials amount, plasticizer type and plasticizer amount on drug release were investigated respectively. Coating solution was achieved by dissolving EC45cps of 21 g, EC100cps of 7 g, DBS of 2.8 g and talcum powder of 8 g in ethanol to get a final volume of 500 ml. Particles of 150g along with 500mL coating solution would be fine. The results showed that with the air volume of 35 m3·h-1, coating temperature of 35o, coating speed of 6 mL·min-1 and proper amount of coating solution, fine microcapsules were obtained. The mean diameter of the microcapsules obtained eventually were 213 micro m and the drug content were 23%, which was suitable for producing a suspension. Particle diameter distribution corresponded to the normal distribution and obviously prolonged drug-release was achieved

Biocompatibility research of a novel pH sensitive ion exchange resin microsphere

The main objective of this study was to investigate biocompatibility and provide in vivo pharmacological and toxicological evidence for further investigation of the possibility of pH sensitive ion exchange resin microsphere for clinical utilizations. Acute toxicity study and general pharmacological studies were conducted on the pH sensitive ion exchange resin microsphere we prepared. The general pharmacological studies consist of the effects of the pH sensitive ion exchange resin microsphere on the nervous system of mice, the functional coordination of mice, the hypnosis of mice treated with nembutal at subliminal dose, the autonomic activities of tested mice, and the heart rate, blood pressure, ECG and breathing of the anesthetic cats. The LD50 of pH sensitive ion exchange resin microsphere after oral administration was more than 18.84 g kg[-1]. Mice were orally administered with 16 mg kg[-1], 32 mg kg[-1] and 64 mg kg[-1] of pH sensitive ion exchange resin microsphere and there was no significant influence on mice nervous system, general behavior, function coordination, hypnotic effect treated with nembutal at subliminal dose and frequency of autonomic activities. Within the 90 min after 5 mg kg[-1], 10 mg kg[-1], 20 mg kg[-1] pH sensitive ion exchange resin microsphere was injected to cat duodenum, the heart rate, blood pressure, breathing and ECG of the cats didn't make significant changes in each experimental group compared with the control group. The desirable pharmacological and toxicological behaviors of the pH sensitive ion exchange resin microsphere exhibited that it has safe biocompatibility and is possible for clinical use

Simultaneous determination of trillin and desgalactotigonin contents in Solanum lyratum by HPLC-ELSD / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a HPLC-ELSD method for simultaneous determination of trillin and desgalactotigonin contents in Solanum lyratum.</p><p><b>METHOD</b>A Diamonsil C18 column (4.6 mm x 250 mm, 5 microm) was adopted, with the mobile phase consisting of acetonitrile-10 mmol x L(-1) ammonium acetate (52: 48). The temperature was 25 degrees C, the flow rate was set at 0.6 mL x min(-1), and the sample size is 20 microL. The temperature of drift tubes and gas flow rate of the detector were set at 95 degrees C and 2.3 L x min(-1), respectively.</p><p><b>RESULT</b>With in the linear ranges of 20-200 mg x L(-1) and 10-100 mg x L(-1), trillin and desgalactotigonin show a good linear relationship. The average recovery was 99.4% (RSD 0.90%) for trillin and 100.3% (RSD 1.1%) for desgalactotigonin.</p><p><b>CONCLUSION</b>The method is so accurate and easily reproducible that it is suitable for the quality control of S. lyratum medicinal materials.</p>

Preparation of two poor water soluble drugs - nanoporous ZnO solid dispersions and the mechanism of drug dissolution improvement / 药学学报

Nanoporous ZnO was used as a carrier to prepare drug solid dispersion, the mechanism of which to improve the drug dissolution was also studied. Nanoporous ZnO, obtained through chemical deposition method, was used as a carrier to prepare indomethacin and cilostazol solid dispersions by melt-quenching method, separately. The results of scanning electron microscope, surface area analyzer, fourier transform infra-red spectroscopy, differential scanning calorimeter and X-ray diffraction showed that drugs were implanted into nanopores of ZnO by physical adsorption effect and highly dispersed into nanopores of ZnO in amorphous form, moreover, these nanopores strongly inhibited amorphous recrystallization in the condition of 45 degrees C and 75% RH. In addition, the results of the dissolution tested in vitro exhibited that the accumulated dissolutions of indomethacin and cilostazol solid dispersions achieved about 90% within 5 min and approximately 80% within 30 min. It was indicated in this study that the mechanism of drug dissolution improvement was associated with the effects of nanoporous ZnO carrier on increasing drug dispersion, controlling drug in nanopores as amorphous form and inhibiting amorphous recrystallization.

Study on Preparation and Stability of the Solid Dispersion of Radix Arnebiae seu Lithospermi / 中成药

Objective: To enhance the dissolution rate in vitro and bioavailability in vivo of the active components of extraction of Radix Arnebiae seu Lithospermi. Methods: Solid dispersion of extract of Radix Arnebiae seu Lithospermi were prepared with solid dispersion technology, X ray diffraction and stability experiments were also carried out. Results: The dissolution rates in vitro of the active components of extraction of Radix Arnebiae seu Lithospermi solid dispersion were obviously raised and stable, and the solid dispersion was not easy to age. Conclusion: The dissolution rate in vitro of the active components in Radix Arnebiae seu Lithospermi can be inproved greatly by the solid dispersion using PVP and HPMC as a carrier.