omeprazole magnesium salt is insoluble in water, and it is in crystalline particle form. It has a good stability and can be stored at room temperature for more than 5 years without color change and content decrease. It can be prepared into a tablet. In addition, tablets made of magnesium salts have the characteristics of sustained-release preparations. Omeprazole magnesium which is insoluble in water will go through a slower release and absorption process in the intestinal tract. Modified with magnesium on the omeprazole, the chemical structure is changed to provide patients new drugs with a more secure, better quality, better effect.
Figure 1: Omeprazole magnesium
Omeprazole can inhibit the secretion of gastric acid, clinically used for treatment of heartburn and acid reflux caused by too much gastric acid. In addition, omeprazole magnesium enteric-coated tablets is used for the treatment of duodenal ulcer, gastric ulcer and reflux esophagitis: combined with antibiotics for the treatment of duodenal ulcer with helicobacter pylori infection ; treatment of non-steroidal anti-inflammatory drug-related peptic ulcer and gastroduodenal erosion; used to prevent non-steroidal anti-inflammatory drug-induced peptic ulcer, gastroduodenal erosion or indigestion symptoms; also for the long-term treatment of chronic relapsing peptic ulcer and reflux esophagitis; symptomatic treatment of heartburn and regurgitation caused by gastro-oesophageal reflux disease; symptomatic treatment of ulcer-like symptoms and acid-related dyspepsia; treatment of Zollinger-Ellison syndrome.
Absorption: omeprazole is absorbed in the small intestine and is usually completely absorbed within 3-6 hours. The bioavailability is about 60% after repeated administration. The intake of food when administration had no effect on its bioavailability. The plasma protein binding rate of omeprazole is 95%, and the apparent volume of distribution is 0.3L/kg.
Metabolism: omeprazole is mainly completely metabolized in the liver, mainly by the catalytic metabolism of CYP2C19 and CYP3A4 enzyme. The metabolites are sulfone, sulfide and hydroxy omeprazole, and these products have no significant effect on gastric acid secretion. Total plasma clearance rate is 0.3-0.6 L/min. Omeprazole can inhibits the catalytic metabolic effects of CYP2C19 of itself, so that the bioavailability of omeprazole is increased by about 50% over single doses in multi-dose therapy.
Excretion: omeprazole plasma elimination half-life is about 40 minutes (30-90 minutes). Approximately 80% of the metabolites are excreted in the urine and the rest is excreted in the feces.
Factors of patient: omeprazole bioavailability did not change significantly in elderly patients or patients with renal dysfunction; while increased in patients with liver dysfunction, but the clearance rate of these patients were significantly decreased.
Dosage: must swallow the whole piece, at least with a cup of liquid delivery service. The tablet cannot be chewed or crushed; it can be dispersed in water or slightly acidic liquid (such as: fruit juice), the dispersion must be taken within 30 minutes.
Determination of acetic acid residues in raw material
Glacial acetic acid is both reactant and the subject to adjust the pH value in the process of producing omeprazole magnesium. The presence of acidic substances will have an impact on the stability of omeprazole magnesium. The product is easy to degrade in the acidic conditions. In order to increase product stability, a stable and economical method is needed for the strict control of glacial acetic acid residue in the drug substance of omeprazole magnesium. Applying HPLC acetic acid residue control, glacial acetic acid can be completely separated from the components of omeprazole magnesium which can be detected. The accuracy is high, and the detection cost is low.
Determination of sulfate in raw material
Ion chromatography has been applied to the determination of the content of sulfate in omeprazole magnesium sulfate. The method is accurate and reliable for the determination of sulfate in the range of 0.1-40.0μg/mL. It can be used for the determination of sulfate impurity in omeprazole magnesium raw material.
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[2] Li Juping, Liu Xiaoping, Jin Yongliang. Determination of acetic acid residues in omeprazole magnesium powder by HPLC [J]. Pharmaceutical Research, 2015 (9): 514-516.
[3] Zhao Changjun, Gao Xinzhen. Determination of sulfate in omeprazole magnesium powder by ion chromatography [J] North Pharmaceutical Journal, 2016, 13 (10): 1-2.
White or almost white, hygroscopic powder.
Omeprazole Magnesium is an inhibitor of gastric secretion. Used as an anttiulcerative.
