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Objective: The present work studied the effect of PVP and surfactant combined carrier on its capability to improve drug absorption.
Materials and methods: PVP K30-Tween 80 combined carries was applied into the astilbin solid dispersions, tested both in vivo in beagle dogs and in vitro in transport experiments across Caco-2 cell monolayers.
Results and discussion: In the animal studies a many fold increase in plasma AUC was observed for the solid dispersions of drug in PVP K30-Tween 80 combined carries compared to active pharmaceutical ingredient (API). The applicability of Caco-2 monolayers as a tool for predicting the in vivo transport behavior of Astilbin in combination with a solubility enhancing carries was shown. In vitro transport studies confirmed the effect of combined carries on the absorption behavior of the astilbin. MTT studies showed the cell viability gradually decreased with the increase of the drug concentration in a dose dependent manner for astilbin and that in solid dispersions. The permeability and apparent permeability coefficients (Papp) increased with drug in the Caco-2 cell.
Conclusion: In this study, it was found that PVP K30 and Tween 80 promoted the permeability of drugs best within a certain amount. For astilbin PVP K30 and surfactant combined carrier had a strong potential to improve oral bioavailability. 相似文献
- 1. (1) It is a piece of stainless steel, with no delicate parts, and can be used in very hostile environments;
- 2. (2) It does not require any cables such as those in the case of thermocouples;
- 3. (3) It is very much cheaper than thermocouples.
This invention has been patented in the USA, UK and Europe with financial and legal support provided by the British Technology Group, UK. Patent application in Japan is still pending.
The invention is particularly useful for life assessment purposes in power and petrochemical plants. The underlying physical principle of the Feroplug is based on the transformation of ferrite, which is ferromagnetic at room temperature, into other phases such as carbide and sigma which are nonferomagnetic at room temperature. The amount of transformation depends on the temperature and duration of exposure. If the amount of transformation and time of exposure is known, the temperature of exposure can be deduced. Thus, the Feroplug makes use of the change in the amount of ferrite, which can be easily detected by room temperature magnetic measurement, to indicate the temperature of exposure. A model has been developed which can describe the ferrite transformation behaviour of Feroplug materials under non-isothermal conditions. The agreement between experimental data and the model is good at temperatures above 550°C. 相似文献