ABSTRACT
Objective To establish a HPLC method for determining the related substances of valsartan and amlodipine tablets. Methods With octadecylsilane chemically bonded silica as the filler,the mixture of triethylamine(adjusting pH to 2.8 with phos-phoric acid)-methanol-acetonitrile was acted as the mobile phase by the gradient elution.The flow rate:1 .0 mL/min.The tempera-ture:40 ℃.The detection wavelength:238 nm.The injection volume:10μL.Results With octadecylsilane chemically bonded sili-ca as the filler,the mixture of triethylamine(adjusting pH to 2.8 with phosphoric acid)-methanol-acetonitrile was acted as the mo-bile phase by the gradient elution.The flow rate:1.0 mL/min.The temperature:40 ℃.The detection wavelength:238 nm.The injection volume:10μL.Conclusion This method is simple and accurate with good system suitability and can be used as the test method for the related substances of valsartan and amlodipine tablets.
ABSTRACT
<p><b>OBJECTIVE</b>To prepare pulsed-release tablet (PTS) according to the rhythm of coronary heart disease based on efficacy material and the mechanism of compound Danshen.</p><p><b>METHOD</b>PTS were achieved by coating the core which contains drugs, CMS-Na, lactose, succinic acid and MCC with separation layer (Eudragit RL), swelling layer (HPMC E5), and controlled-release membrane (Eudragit RS-RL-EC).</p><p><b>RESULT</b>The results of in vitro experiments showed that no difference was observed among the profiles of Danshensu, protocatechuic aldehyde, ginsenoside Rg1, Rb1, notoginsenoside R1 release from the two-step release system. And it indicated that swelling was the basis and prerequisite for drug release from PTS, and the diffusion, organic acid-induced, and osmotic pumping mechanism were involved in drug release, but the latter they were the dominant factors.</p><p><b>CONCLUSION</b>Successfully obtained the PTS of a certain lag-time behind the rapid release which indicate that after bed time administration of such device, the drug plasma concentration-time curve CAN meet the requirements of chronotherapy of cardiovascular disease.</p>
