Pulmonary Selectivity and Local Pharmacokinetics of Ambroxol Hydrochloride Dry Powder Inhalation in Rat

Evaluation of safety and efficacy of inhaled ambroxol in hospitalized adult patients with mucopurulent sputum and expectoration difficulty

Background

Ambroxol is a widely used mucoactive drug in sputum clearance of respiratory diseases taken orally and by injection. However, there is a paucity of evidence for inhaled ambroxol in sputum clearance.

Methods

This study performed a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial at 19 centers in China. Hospitalized adult patients with mucopurulent sputum and expectoration difficulty were recruited. Patients were randomized by 1:1 to receive inhalation of either ambroxol hydrochloride solution 3 mL (22.5 mg) + 0.9% sodium chloride 3 mL or 0.9% sodium chloride 6 mL twice daily for 5 days, with an interval of more than 6 h. The primary efficacy endpoint was the absolute change in the sputum property score after treatment compared to the baseline in the intention-to-treat population.

Results

Between 10 April 2018 and 23 November 2020, 316 patients were recruited and assessed for eligibility, of whom 138 who received inhaled ambroxol and 134 who received a placebo were included. Patients who received inhaled ambroxol had a significantly greater decrease in the sputum property score compared with patients who received inhalation of placebo (difference: -0.29; 95% CI: -0.53 to -0.05; p = 0.0215). Compared with the placebo, inhaled ambroxol also significantly reduced more expectoration volume in 24 h (difference: -0.18; 95% CI: -0.34 to -0.03; p  = 0.0166). There was no significant difference in the proportion of adverse events between the two groups, and no deaths were reported.

Discussion

In hospitalized adult patients with mucopurulent sputum and expectoration difficulty, inhaled ambroxol was safe and effective for sputum clearance compared with a placebo.

Clinical trial registration

[https://www.chictr.org.cn/showproj.html?proj=184677], Chinese Clinical Trial Registry [ChiCTR2200066348].

Baicalin/ambroxol hydrochloride combined dry powder inhalation formulation targeting lung delivery for treatment of idiopathic pulmonary fibrosis: fabrication, characterization, pharmacokinetics, and pharmacodynamics

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal lung disease caused by multiple factors. Currently, safe, and effective drugs for the treatment of IPF have been extremely scarce. Baicalin (BA) is used to treat pulmonary fibrosis, IPF, chronic obstructive pulmonary disease, and other lung diseases. Ambroxol hydrochloride (AH), a respiratory tract lubricant and expectorant, is often used to treat chronic respiratory diseases, such as bronchial asthma, emphysema, tuberculosis, and cough. The combination of BA and AH can relieve cough and phlegm, improve lung function, and potentially treat IPF and its symptoms. However, given the extremely low solubility of BA, its bioavailability for oral absorptions is also low. AH, on the other hand, has been associated with certain side effects, such as gastrointestinal tract and acute allergic reactions, which limit its applicability. Therefore, an efficient drug delivery system is urgently needed to address the mentioned problems. This study combined BA and AH as model drugs with L-leucine (L-leu) as the excipient to prepare BA/AH dry powder inhalations (BA/AH DPIs) using the co-spray drying method. We the performed modern pharmaceutical evaluation, which includes particle size, differential scanning calorimetry analysis, X-ray diffraction, scanning electron microscope, hygroscopicity, in vitro aerodynamic analysis, pharmacokinetics, and pharmacodynamics. Notably, BA/AH DPIs were found to be advantageous over BA and AH in treating IPF and had better efficacy in improving lung function than did the positive drug pirfenidone. The BA/AH DPI is a promising preparation for the treatment of IPF given its lung targeting, rapid efficacy, and high lung bioavailability.

Safety of ambroxol in the treatment of airway diseases in adult patients

INTRODUCTION

Ambroxol is a widely used secretolytic and mucoactive over-the-counter agent primarily used to treat respiratory diseases associated with viscid mucus. Following post-marketing reports of hypersensitivity reactions and severe cutaneous adverse reactions (SCARs) possibly linked to ambroxol, the European Union's Pharmacovigilance Risk Assessment Committee (PRAC) initiated in April 2014 a review of the safety of ambroxol in all its registered indications, which was finalized in 2016. Areas covered: Here, we evaluate the clinical safety of ambroxol and provide an expert opinion on the benefit-risk balance of ambroxol in the treatment of adult patients with bronchopulmonary diseases. The evidence for this review is derived from clinical trials of ambroxol that were provided to the PRAC by the marketing authorization holders of ambroxol-containing medicines. Expert opinion: Clinical experience accumulated from randomized clinical trials and observational studies suggests that ambroxol is a safe and well-tolerated treatment of bronchopulmonary diseases, with a well-balanced and favorable benefit-risk profile. All reported adverse events were mild and self-limiting, and the risk of SCARs with ambroxol is low. Further investigations could address the safety and efficacy of ambroxol in pediatric lung diseases and in additional therapeutic indications, such as biofilm-dependent airway disease and lysosomal storage disorders.

Effects of the expectorant drug ambroxol hydrochloride on chemically induced lung inflammatory and neoplastic lesions in rodents

Ambroxol hydrochloride (AH) is an expectorant drug used to stimulate pulmonary surfactant and serous airway secretion. Surfactant proteins (SPs) are essential for maintaining respiratory structure and function, although SP expression has also been reported in lung inflammatory and proliferative lesions. To determine whether AH exerts modulatory effects on these lung lesions, we examined its effects on pleural thickening induced by intrathoracic administration of dipotassium titanate (TISMO) in A/JJmsSlc (A/J) mice. We also analyzed the modulatory effects of AH on neoplastic lung lesions induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in A/J mice and by N-nitrosobis (2-hydroxypropyl) amine (DHPN) in F344/DuCrlCrj (F344) rats. A/J mice treated with TISMO showed decreased body weight, increased white blood cell (WBC) counts, and pleural thickening caused by pleuritis and poor general condition. However, A/J mice treated with TISMO + 120 ppm showed significant recovery of body weight and WBC counts to the same levels as those of A/J mice not treated with TISMO, although no significant differences were observed in histopathological changes including the immunohistopathological expression of IL-1β in the lung and maximum pleural thickness regardless of AH treatment. In the NNK and DHPN experiments, no significant differences in body weight, hematology, plasma biochemistry, and histopathological changes were associated with AH concentration. These results suggest that AH potentially exerts anti-inflammatory effects but does not have a direct suppressive effect on lung tumorigenesis in rodents.

Ambroxol: a multifaceted molecule with additional therapeutic potentials in respiratory disorders of childhood

INTRODUCTION

Mucoactive drugs are currently used to cleanse the respiratory tract following disturbance of the normal mucociliary clearance due to mucous hyperproduction and/or modification of its physicochemical characteristics. However, in addition to possessing the ability to perform specific actions on airway secretion, these compounds have the capability to modulate the mechanisms involved in abnormal secretions. Indeed, over the years, in the postmarketing phase, a large number of studies have been published showing interesting pharmacological activities in addition to their secretagogue activity.

AREAS COVERED

This article collates available data on ambroxol (2-amino-3,5-dibromo-N-[trans-4-hydroxycyclohexyl]benzylamine), a metabolite of bromhexine, used as a secretagogue in the treatment of childhood airway diseases. This article goes beyond the mucoactive aspects of the drug covering its multiple pharmacological properties.

EXPERT OPINION

The non-mucoactive functions exhibited by the compound may provide beneficial effects on airway structure and function in health and disease. Beyond the mucokinetic and secretagogue effects, ambroxol showed great antioxidant, anti-inflammatory, local anesthetic and surfactant synthesis stimulatory activities. Moreover, some antiviral and antibacterial activities were shown. These findings may better explain the clinical results observed in a variety of airway disorders and suggest additional therapeutic potential. Further studies are needed to better define the clinical relevance of these non-mucolytic activities.