Expectorants
Ambroxol Hydrochloride is also known as hydrochloric acid bromine cyclohexylamine alcohol. Its chemical name is trans-4-[(2-amino-3, 5-dibromo-benzyl) amino] cyclohexanol hydrochloride, it is the active metabolite of the expectorants bromhexine (N-demethylation, a trans-hydroxy group has been introduced into the para position of cyclohexyl group) with its toxicity being lower than bromhexine but the activity being higher than bromhexine.
Ambroxol hydrochloride is a kind of grume dissolving agent developed by the Boehringer Ingelheim Company (Germany), and had first entered into market in Germany in the early 1980s. It has been subsequently approved for entering into France, Italy, Japan, Spain and many other countries. As a new generation of sputum dissolving agent, it can improve the expectoration, and has effect on promoting the secretion of the lung surfactant and airway as well as the ciliary movement. Clinically it can be used for adjusting the secretion of grume and pulp, activation of swing of the ciliary. It can make it easy for sputum dissolution, strengthen the outward transport of sputum and make it easy for being discharged. It can also promote the biosynthesis of lung surfactant and maintain the tension of the alveoli and the functional parameter of the lung function; promote the antibiotics to penetrate through the tissues, increase their concentrations and enhance the bactericidal effect; it has antioxidant effect and can reduce the release of inflammatory mediators and reduce the inflammation reaction; it also has synergistic effect with bronchial spasmolysis and improve the efficacy of the antispasmodic drugs. Therefore, this drug can be clinically widely applied to the acute and chronic respiratory disorders accompanied with abnormal secretion of respiratory tract, especially to the expectorant treatment of chronic bronchitis, respiratory distress syndrome of newborns and the adjuvant therapy of the lung surgery. It has advantages such as low toxicity, accurate efficacy and excellent synergistic effect when being used together with antibiotics. All the above points make it be a common expectorant.
Pharmacological effects
1. The role of relieving cough and reducing sputum
Ambroxol hydrochloride majorly take effect on the respiratory secretory cells, regulating the secretion of mucous and serous substance, increasing the slurry secretion, degrading the polysaccharide fibers of the acidic glycoprotein in the sputum, inhibiting the synthesis of the acidic protein in the mucous glands and goblet cells, reducing the viscosity of sputum, making the sputum thin and be easy to be discharged; meanwhile, the drug may also increase the frequency of respiratory cilia movement and strength and promote the mucus discharge and respiratory self-purification.
2. Antioxidant effect
Ambroxol hydrochloride has a significant antioxidant effect and can have a significant effect on the reactivity of the free oxygen radicals associated with the lung disease lesions. Studies have shown that ambroxol has strong inhibitory effect on the H2O2 produced by the neutrophils; in addition, ambroxol can also activate the intracellular glutathione system, promote the biosynthesis of the intracellular glutathione (GSH), thereby causing damaging effects on the oxygen free radicals.
Synthesis method
Take the O-nitrobenzaldehyde as the starting material, has it reacted with trans-4-aminocyclohexanol to obtain the compound 3 , and then use special catalyst such as modified Pd/C and simultaneous reduction of the nitro group and C = N group to give compound 2 ; finally use HBr/H2O2 for bromination and apply hydrochloric acid to give ambroxol hydrochloride 1 .
Figure 1 is the synthesis route of the ambroxol hydrochloride
Clinical application
1. Application of the respiratory system
Ambroxol hydrochloride can increase the serous secretion in the airway serous, dilute the sputum so that it is easy to be discharged, thereby improving the condition of the respiratory health, enable the PS in the respiratory tract being able to play a normal protective effect; meanwhile, it also has a high affinity to the lungs and can promote the biosynthesis and secretion of the lung PS, thereby maintaining the stability of the alveoli, which will help to improve the alveoli function. Thus, the early application of ambroxol hydrochloride can alleviate the airway obstruction, improve ventilation, shorten the course and reduce any kinds of complications. It is commonly applied to the treatment of chronic bronchitis exacerbation, asthmatic bronchitis, and pneumonia as well as lung abscess embolism.
2. Application in the age-related chronic obstructive pulmonary disease (COPD)
COPD is a common disease of the respiratory tract. With the increase of the age, the clearance function of the airway mucociliary in the elderly gradually declines, reduce the lung antioxidant. The ambroxol has various functions including anti-inflammatory, antioxidant and enhance the ciliary movement, etc., it can improve the clearance capability of the airway epithelial surface, thus preventing the occurrence of COPD.
3. Clinical application in the respiratory system of newborn
Neonatal respiratory distress syndrome (NRDS) is caused by the lack of the pulmonary surfactant (PS). Ambroxol can promote the biosynthesis and secretion of the endogenous PS, boost the alveolar type II cells to release more endogenous PS, thereby reducing the surface tension of the alveoli, making the atrophic alveoli be re-inflated, further improving lung function and shortening the duration of mechanical ventilation and duration of oxygen therapy, reducing the risk factors caused by bronchial pneumonia.
4. Lung protection effect after the cardiopulmonary bypass surgery (CPB)
Lung injury after cardiopulmonary bypass surgery is the most common complication after the cardiothoracic surgery. Foreign studies have confirmed that, after the CPB, lung is subject to the ischemia-reperfusion injury. The neutrophils and platelets are activated, accumulate in the lungs, attach to the capillary wall of the lung and release large amounts of oxygen free radicals, inflammatory mediators which cause damage to the alveolar type II cells and vascular endothelial cells, thereby resulting in the decrease of the biosynthesis and release of PS. In addition, the alveolar-capillary membrane permeability has also been increased; alveolar fluid accumulates; PS undergoes over-consumption and is not able to play normal physiological effects, increasing the alveolar surface tension; moreover, the alveoli tends to collapse, leading to respiratory disorders. Ambroxol hydrochloride can effectively promote the synthesis and secretion of PS after the thoracic surgery, inhibit the activated neutrophil response, reduce the airway resistance and the airway hyperresponsiveness, affecting the ion transport and the potential difference of the airway wall and reduce lung injury after cardiopulmonary bypass surgery.
Precautions
1. Disable: Patients who are allergic to this drug; three months before the pregnancy.
2. Caution: Patients of malignant cilia syndrome; patients of liver and kidney dysfunction; patients of gastric ulcer. glaucoma; women in medium or late pregnancy or breast-feeding women.
3. The cooperated treatment between this product and antibiotics (such as amoxicillin, cefuroxime and erythromycin, etc.) can improve the antibiotic concentration in the lung tissue.
4. There are occasional mild adverse reactions in the gastrointestinal tract with the symptoms disappearing after dose reduction.
This information is edited by Xiongfeng Dai from Chemicalbook.
Acute toxicity
Oral-rat LD50: 4203 mg kg; Oral-Mouse LD50: 2380 mg/kg.
Chemical Properties
White Crystalline Powder
Uses
Ambroxol hydrochloride is a medication indicated to alleviate chest congestion associated with conditions that include bronchitis, pneumonia, bronchospasm asthma, cough, and allergy. Preclinically, ambroxol, the active ingredient of Mucosolvan, has been shown to increase respiratory tract secretion. It enhances pulmonary surfactant production and stimulates ciliary activity.
Definition
ChEBI: Ambroxol hydrochloride is an aromatic amine. it is a metabolite of bromhexine that stimulates mucociliary action and clears the air passages in the respiratory tract. it is usually administered as the hydrochloride.
Indications
Ambroxol Hydrochloride is a bronchosecretolytic drug. It is indicated as “secretolytic therapy in bronchopulmonary diseases associated with abnormal mucus secretion and impaired mucus transport. It promotes mucus clearance, facilitates expectoration and eases productive cough, allowing patients to breathe freely and deeply.
Biological Activity
Sodium channel blocker and mucolytic agent with antioxidant, anti-viral and anti-inflammatory properties. Inhibits tetrodotoxin (TTX)-resistant channels more potently than TTX-sensitive subtypes (IC 50 values for tonic block are 35.2 and 111.5 μ M respectively). Inhibits release of histamine, leukotrienes and cytokines from human leukocytes and mast cells.
Mode of action
Ambroxol is the active metabolite of bromhexine. Ambroxol causes an increase in secretion in the respiratory tract. It promotes surfactant production and stimulates ciliary activity. These effects assist the flow of mucus and its removal (mucociliary clearance). An improvement in mucociliary clearance was demonstrated in clinical pharmacological studies. The increase in secretion and mucociliary clearance facilitate expectoration and reduce the cough. In in vitro studies ambroxol showed a significant reduction in cytokine release, both in the blood and in mononuclear and polynuclear cells. The clinical relevance of these findings is unclear.
