Intelligent microwave digestion of Olmesartan ester hydrochlorothiazide tablets

1. Preface

Olmesartan axetil hydrochlorothiazide tablets, each tablet containing 20mg of olmesartan axetil and 12.5mg of hydrochlorothiazide, are a relatively ideal antihypertensive drug. It has a good therapeutic effect on all types of hypertension. Its prominent feature is a long half-life and it can effectively control blood pressure within one day. Microwave digestion was selected for the pretreatment of olmesartan ester hydrochlorothiazide tablet samples to explore the most suitable digestion parameters. This method also has the characteristics of high recovery rate and low blank, which is conducive to the subsequent rapid and accurate determination of various inorganic elements.

2 Instruments and reagents

2.1 Instruments

Digipol-MWD30 fully automatic intelligent microwave digestion instrument, acid eliminator, analytical balance (one part per 100,000), etc.

2.2 Reagents

Nitric acid (68%), hydrochloric acid (37%), hydrofluoric acid (40%), hydrogen peroxide (30%

3 Experimental Methods

Weigh one sample of olmesartan ester hydrochlorothiazide tablets, with a mass of approximately 0.22g (accurate to 0.1mg), add 5mL of nitric acid, 2mL of hydrochloric acid, 1mL of hydrofluoric acid and 1mL of hydrogen peroxide, let it stand for about 15 minutes. After no obvious reaction occurs, assemble the digestion tank.

Conduct the experiment according to the following set parameters:

After the experiment, when the temperature drops below 60℃, take out the digestion tank and transfer it to a fume hood. Slowly open it and place it on an acid-expulator at 150℃ to expulate the acid to about 0.5mL. Then transfer it to a volumetric flask and make up the volume. The digestion solution should be clear and transparent, and the sample should be completely dissolved.

4 Result

The sample of olmesartan ester hydrochlorothiazide tablets selected for the experiment was approximately 0.22g. The experiment was conducted using a mixed acid system of nitric acid + hydrochloric acid + hydrofluoric acid + hydrogen peroxide. The maximum experimental temperature was 210℃, and the temperature was maintained for about 30 minutes. The sample could be completely digested.