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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.
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Objective To develop the formulation of self-microemulsifying drug delivery system for hawthorn leaves flavonoids (HAW-SMEDDS). Methods The optimum formulations of oil phase, surfactant, and assistant surfactant for HAW-SMEDDS were screened by solubility test, compatibility test, and pseudo-ternary phase diagrams, with the time of formulating microemulsion, the consequence of visual examination, and particle size as indexes. The dissolution of HAW-SMEDDS was measured, taking the commercial tablet Yixintong Tablet as reference. Results The optimum self-microemulsifying drug delivery system was composed of Labrasol (35%), Transcutol P (10%). The particle diameter was (39.5?5.4) nm, the time of self-microemulsifying was less than 1 min. The percent of accumulated dissolution of hawthorn leaves flavonoids in SMEDDS in distilled water was up to 70% at 10 min, while that in the Yixintong Tablet was less than 50% at 60 min. Conclusion The formulation of HAW-SMEDDS preparation could meet the request of the design. It could provide the reference for the new dosage form.
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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.
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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.