Pharmacodynamic Evaluation of Novel Tetrandrine-loaded Chitosan Microspheres

Background: Tetrandrine has good pharmacological effects, especially in the treatment of pulmonary hypertension. It has the potential to be valuable for clinical applications, however the poor solubility and the high variability of oral bioavailability greatly limited its development. Our research group prepared a new type of tetrandrine microspheres by using chitosan. However, it was lack of pharmacodynamic evaluation and difficult to evaluate if the application of this dosage form can really meet the target to improve curative effect. Methods: In this study, we established animal model of rats with hypoxic pulmonary hypertension, and evaluated acute therapeutic effect by prepared tetrandrine microspheres. Results: In vivo pharmacodynamic showed that tetrandrine lung targeting microspheres had stronger and longer effect to reduce pulmonary arterial pressure (mPAP) than aqueous solvent. After apply tetrandrine lung targeting microspheres on hypoxia rats, no matter the level of dose, mSBP all had no obvious change. Conclusion: Thus it indicated that tetrandrine lung targeting microspheres were mainly effective inside lung, with certain selectivity.