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Effects of Oral Mucolytics on Tear Film and Ocular Surface

This study has been completed.
Information provided by (Responsible Party):
Young Joo Shin, Hallym University Kangnam Sacred Heart Hospital Identifier:
First received: October 22, 2012
Last updated: August 29, 2016
Last verified: August 2016

Ambroxol is a metabolite of bromhexine and possesses mucokinetic and secretolytic properties that are also found in mucolytic agents.1 Ambroxol has been used for decades for the treatment of respiratory disorders associated with excessive mucus, including chronic inflammatory pulmonary conditions, bronchitis, and pneumonia.2,3 The drug changes the biophysical properties of secretions by degrading the mucin polymers, deoxyribonucleic acid, fibrin in airway secretions, and by generally decreasing viscosity.4 In addition, ambroxol increases cyclic nucleotide (cAMP or cGMP),5 which can theoretically increase tear secretion.6 Many systemic medications, such as antihistamines, antidepressants, diuretics, acne drugs, and certain blood pressure medicines can cause or exacerbate a dry eye.7,8 On the other hand, several topical medications, including mucolytics such as ambroxol and bromhexine, may be used to treat tear-deficient dry eyes by promoting lacrimal gland function.9 However, the effects of mucoactive agents on the tear film have not been investigated systemically, and mucoactive agents may have a disturbing effect on the tear film because they modify mucin.10,11 The tear film is composed of 3 unique layers, including the outermost lipid layer, the middle aqueous layer, and the innermost mucus layer; this structure enables it to perform many functions.12 The lipid layer acts as a barrier to prevent tear film evaporation, and the aqueous layer supplies oxygen and important nutrients to the cornea.13 The mucin layer, secreted mostly by conjunctival goblet cells, coats the corneal surface rendering it hydrophilic, and anchors the tear film to the corneal surface.14 Deficiencies in the amount of tear production or alteration in tear composition can lead to ocular surface disease.15 Although many studies have focused on aqueous-deficient dry eye syndrome,16-18 the effect of mucin layer defects on the tear film has not been thoroughly studied. Furthermore, very few reports have determined the effects of oral mucolytic agents on the tear film and ocular surfaces, although a study has reported that filamentary keratopathy was treated with debridement of filaments and application of topical mucolytic agents such as acetylcysteine eyedrops. In the present study, we investigated the effects of oral ambroxol on tear film and ocular surface.


  1. Malerba M, Ragnoli B. Ambroxol in the 21st century: pharmacological and clinical update. Expert Opin Drug Metab Toxicol 2008;4:1119-1129.
  2. Rubin BK. Mucolytics, expectorants, and mucokinetic medications. Respir Care 2007;52:859-865.
  3. Rogers DF. Mucoactive agents for airway mucus hypersecretory diseases. Respir Care 2007;52:1176-1193.
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Condition Intervention Phase
In the Present Study, we Investigated the Effects of Oral Ambroxol on Tear Film and Ocular Surface.
Drug: Ambroxol hydrochloride (Mucopect®, 60 mg, Boehringer Ingelheim)
Phase 1
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Participant)
Primary Purpose: Health Services Research

Resource links provided by NLM:

Further study details as provided by Hallym University Kangnam Sacred Heart Hospital:

Primary Outcome Measures:
  • Visual analog pain score [ Time Frame: 1 day ]
    Visual analog pain score Subjective discomfort or pain was graded numerically using the VAS. The scale range was 0 (absence of pain) to 10 (maximal pain). Subjects were asked to describe their symptoms using the VAS.

  • Fluorescein staining [ Time Frame: 1 day ]
    Corneal fluorescein staining was examined with a biomicroscope under blue-light illumination after fluorescein instillation into the tear film. The corneal surface was divided into 5 areas (1 center zone and 4 peripheral zones). Corneal erosion staining was recorded using a standardized grading system of 0 to 3 for each of the 5 areas.

  • Tear break up time [ Time Frame: 1 day ]
    Fluorescein was placed in the lower conjunctival sac using a fluorescein strip (HAAG-STREIT, Köniz, Switzerland), and the time between the last blink and the first appearance of a dark spot was measured using the cobalt blue light of a slit lamp. This procedure was repeated 3 times, and the average value was recorded.

  • Fluorescein clearance test [ Time Frame: 1 day ]
    After applying 1 drop of 0.5% proparacaine hydrochloride to each eye, the inferior fornix was carefully dried with tissue paper. Fluorescein was then applied to the inferior fornix of each eye. The patient continued to sit in the examination room under ambient light and was asked to blink normally. After 10 minutes had elapsed, as determined by a timer, a Schirmer paper strip was inserted into the inferior fornix of each eye at a position approximately one-third lateral to the temporal caruncle. This maneuver was repeated for 3 times over a period of 30 minutes at 10-minute intervals.

  • Schirmer's test [ Time Frame: 1 day ]
    One drop of 0.5% proparacaine hydrochloride (Alcaine, Alcon, Forth Worth, TX, USA) was instilled in the conjunctival sac for topical anesthesia. In a silent room, filter paper (Color Bar, EagleVision, Memphis, TN, USA) was placed in the inferolateral one-third of the lower lid. Care was taken to prevent the paper from contacting the cornea. After 5 minutes, the level of strip wetting (in millimeters) was measured.

Enrollment: 20
Study Start Date: August 2011
Study Completion Date: October 2011
Primary Completion Date: October 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: ambroxol

Ambroxol hydrochloride (Mucopect®, trans-4[2-amino-3.5-dibrombenzylamino]-cyclohexanhydro-chloride, 60 mg, Boehringer Ingelheim) was administered orally to subjects in the ambroxol group immediately after initial examination (10 AM).

one dose for one day

Drug: Ambroxol hydrochloride (Mucopect®, 60 mg, Boehringer Ingelheim)
No Intervention: control


Ages Eligible for Study:   25 Years to 29 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Twenty healthy male volunteers aged between 25 and 29 years

Exclusion Criteria:

  • Subjects with dry eye symptoms within the previous 6 months were excluded from the study.
  • Subjects have any systemic diseases such as systemic lupus, rheumatoid arthritis, Sjögren's syndrome or a history of ocular disease.
  • Subjects have disorder of lid margin, nasolacrimal duct, and cornea.
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Please refer to this study by its identifier: NCT01713179

Korea, Republic of
Hallym University, Kangnam Sacred Heart Hospital
Seoul, Korea, Republic of, 150-950
Sponsors and Collaborators
Hallym University Kangnam Sacred Heart Hospital
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Young Joo Shin, Assistant Professor, Hallym University Kangnam Sacred Heart Hospital Identifier: NCT01713179     History of Changes
Other Study ID Numbers: 2011-07-63
Study First Received: October 22, 2012
Last Updated: August 29, 2016

Additional relevant MeSH terms:
Respiratory System Agents processed this record on April 28, 2017