methylcellulose and baicalin

Baicalin has been reported to have anti-inflammatory and anti-cataract effects on eye tissues, but it has a low bioavailability partly due to its poor stability of baicalin, the special anatomic structure and efficient protective mechanism of eyes. The aim of this study was to investigate the correlation between the stability of baicalin and in situ pH-triggered gelling system. Carbopol(®) 974P (0.3%, w/v) was used as the gelling agent combined with hydroxypropylmethylcellulose E4M (0.6%, w/v) which acted as a viscosity enhancing agent. In vitro and in vivo evaluations were performed using several techniques, namely confocal scanning light microscopy analysis, rheometry, Gamma scintigraphic technique and microdialysis method. The rheological behavior showed a significant enhancement in gel strength under physiological conditions, and the formulation provided sustained release of the drug over an 8-h period. In elimination studies, the radioactivity of formulation was always higher than that of the control solution. Additionally, the AUC and C(max) values were 6.1-fold and 3.6-fold higher than those of the control solution, respectively. The results demonstrated that an in situ pH-triggered gelling system have better ability to keep baicalin stable and retain drug release than marketed baicalin eye drops to enhance the ocular bioavailability.

Topics: Acrylates; Animals; Anti-Inflammatory Agents, Non-Steroidal; Area Under Curve; Biological Availability; Delayed-Action Preparations; Drug Delivery Systems; Drug Stability; Excipients; Flavonoids; Gels; Hydrogen-Ion Concentration; Hypromellose Derivatives; Methylcellulose; Microscopy, Confocal; Rabbits; Rheology; Viscosity

To study the preparation of fufangxiaoyepipa dispersible tablets and evaluate its quality.. Using the disintegration time as index to screen out the best prescription of the dispersible tablets by orthogonal design.. The prescription assembly was 40% of extraction, 15% of MCC, 18% of CCMC-Na, 25% of Calcium sulfate, 2% of Magnesium stearate, the disintegration time met the provision of Pharmacopoeia.. The dispersible tablets dissolve faster and disperse uniformly and the dissolution percent in vitro is obviously superior to the conventional tablets, improving the bioavailability of the preparation.

Topics: Analysis of Variance; Calcium Sulfate; Drugs, Chinese Herbal; Eriobotrya; Excipients; Flavonoids; Methylcellulose; Particle Size; Plants, Medicinal; Quality Control; Reproducibility of Results; Solubility; Tablets; Technology, Pharmaceutical