| From 80's, angiocardiopathy has became the first important disease that threat human health. As WHO estimated that about 20% adult was suffering from hypertension. It was reported that in China, the hypertension patient population has already reached 160 million and there was 50% angiocardiopathy patients died from hypertension. So, developing and manufacturing new drug for hypertension was the main task in many institutions inland and outside.There are six types of drugs to treat hpyertension. Previously Angiotensin converting enzyme inhibitors (ACEI) and Calcium antagonist have main market share. But now angiotesin II (AII) receptor antagonist as a new treating hypertension drug has been paid close attention to. The WHO has listed it in '99 hypertension manual'. Also the drug was found to have the activity to treat heart-failure and conservancy renal function.All receptor antagonist has the following characteristics: (1) High lipotropy, it has high affinity to specific All bind site in various tissues;(2) High selectivity, it has much greater affinity (>3,000 fold) for the ATI receptor than for the AT2 receptor;(3) High specificity, it has no affinity to other receptor;(4) No excitomotor activity, it has no vaso-active action to exsomatize vaso-smooth muscle;(5) No ACEI activity, not effect AI transfering to All and not strengthen the bradykinin's pressure reduction potency. Bradykinin seems to be related to much adverse effection caused by ACEI, include cough, angioneurotic edema and hypotension. All receptor antagonist won't cause these adverse effects that described above. So if patient got cough and angioneurotic edema that caused by ACEI, All receptor antagonist will be a good succedaneum. Sartan's drug is the main kind of All receptor antagonist. Presently the available Sartan's drug in China's marketing is losartan, valsartan and irbesartan.Telmisartan is a new and efficient angiotensin II receptor antagonist and used for the treatment of essential hypertension. Telmisartan has a longer terminal elimination half-life than other commercially available sartans drugs(>24 h), making it suitable for once-daily dosing. It showed more efficient (6 folds) than losartan, butit doesn't affect other receptor systems involved in cardiovascular regulation. Telmisartan has much greater affinity (>3,000 fold) for the ATI receptor than for the AT2 receptor. Telmisartan does not inhibit ACE, and not bind to or block other hormone receptors or ion channels.Telmisartan was developed for treating original hypertension by Boehringer Ingelheim in German. It was gone on the market in America in February of 1999 and in England in February of 2000. There were three kinds' dosage forms as tablets, capsules and compound preparation. In 2004, only one pharmaceutical factory had been approved to manufacture telmisartan and its dosage and go on market in our country.The object of this research is to establish the quality standard of telmisartan and test its stability. Based on the experimental results such as study of telmisartan's characterization, identification tests, the detection of related substances, residual organic solvent and assay of telmisartan, we established the methods to identify the telmisartan by chemical reaction, spectrometry (infrared spectrometry and ultraviolet spectrometry) and chromatography (HPLC). By using HPLC, therelated substances were detected. The method of detecting methylenechloride, chloroform and methanol is established by using gas chromatography and the analytical method for determining the content of telmisartan by HPLC was validated. Based on all experimental results, we developed the standard for quality control of telmisartan, and investigated the product stability including the influencing factors of its stability and accelerate test of stability and long-term stability test. All these results showed that telmisartan is stable to light, humidity and heat.This study provides the evidence for storage condition and period of validity, and makes reference to the manufacture technique of preparations.
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