Mao S.-S.,Guangdong Academic of Medical science |
Zhang W.-J.,Sun Yat Sen University |
Li J.,Sun Yat Sen University |
Ma J.,Guangdong Academic of Medical science
Journal of Biomaterials and Tissue Engineering | Year: 2015
Lidocaine hydrochloride (LH) is an amide local anesthetic and it provides pain relief by inhibiting the influx of sodium ions involved in the initiation and conduction of nerve impulses associated with the perception of pain. Therefore, to relieve the severe post operative pain transdermal patches of lidocaine hydrichoride were prepared by solvent casting method. The prepared formulations were characterized for drug content, thickness, weight uniformity, folding endurance, percentage moisture content, water vapor permeability, and percentage elongation break test in-vitro diffusion and for in vivo analgesic activity. Drug content in all formulation was observed within the range of 83.01 ± 0.1 to 89.24±0.3%. Other physicochemical parameters showed optimum values with little variations. The in-vitro diffusion study was carried out with the rat abdominal skin using Franz diffusion cell. Formulation TL6 (containing HPMC and PVP) showed maximum drug diffusion and formulation TL1 (containing HPMC and EC) showed least drug diffusion after 24 h. In vivo analgesic activity was performed by two different models (hot plate and writhing method) in Wistar rats. Formulation TL6 showed the best analgesic effect in hot plate method and it was confirmed by the writhing method which showed 57.5% analgesia. Therefore, it can be concluded that the transdermal patches of LH can be used in effective management of severe postoperative pain. © 2015 American Scientific Publishers. All rights reserved.
Cui J.,Guangdong Academic of Medical science |
Chen Y.,Guangdong Academic of Medical science |
Zhang G.,Guangdong Academic of Medical science |
Xu L.,Guangdong Academic of Medical science
Experimental and Clinical Cardiology | Year: 2014
Objective: To assess the effect and mechanisms of the thromboxane A2 and endothelin-1 on vascular reactivity in chronic obstructive pulmonary disease (COPD). Methods: Intrapulmonary arterial rings were collected from normal tissues taken from lung cancer patients with or without COPD during pulmonary lobectomy and used to evaluate vascular tone changes in response to 60 mM KCL (reference), the thromboxane A2 analogue U46619, or endothelin-1, as measured with a myograph. Vascular reactivity to U46619 or endothelin-1 was also measured after pretreatment with indomethacin (a COX inhibitor) or L-NAME (an endothelial nitric oxide synthase inhibitor), respectively. Results: The mean contraction of human intrapulmonary arterial rings in response to 60 mM KCL was similar between the COPD and control (without COPD) groups. The contraction response to U46619 or endothelin-1 in the COPD artery group was significantly less than that of the control artery group. L-NAME markedly inhibited the vasoconstriction due to ET-1 in both groups, but indomethacin only inhibited the constriction of U46619 in the control group, and dramatically. Conclusion: Our results suggest that the decreased contractibility of intrapulmonary arterial rings in patients with COPD may be associated with elevated levels of endogenous thromboxane A2 and endothelin-1 that occur during the pathogenesis of COPD.