Interstitial lung disease (ILD) often affects distal lung, and the evaluation of drug distribution to the relevant lung compartments is essential for development of new treatment options. This single center study will utilize samples obtained by transbronchial cryobiopsy (TBCB) procedure to assess the distribution of inhaled drugs in the lungs of the subjects with fibrotic lung disease using mass spectrometry techniques. The study will have a single visit and will include approximately 20 adult subjects with suspected fibrotic ILD and requiring TBCB as part of their diagnostic assessment. This will provide TBCB samples from up to 20 subjects, up to 5 of whom may also provide endobronchial forceps biopsy samples. The study will have 3 phases including screening to check the eligibility, biopsy phase in which all subjects will receive nebulized ipratropium bromide 500 microgram (mcg) for 10 minutes immediately before undergoing bronchoscopy and follow up phase from 7 to 14 days after the procedure. Drug distribution in the lung will be assessed by analyzing biopsy samples collected using mass spectrometry and imaging techniques.

Inclusion Criteria:

• 18 and above years of age inclusive, at the time of signing the informed consent.
• Subjects with suspected ILD listed for TBCB for clinical reasons following review by the ILD services at University College London Hospitals (UCLH) in whom diagnosis has remained unclear following radiological and clinical assessment.
• A subject with a clinical abnormality or laboratory parameter(s) which is/are not specifically listed in the inclusion or exclusion criteria, outside the reference range for the population being studied, may be included only if the investigator in consultation with the Medical Monitor agree and document that the finding is unlikely to introduce additional risk factors and will not interfere with the study procedures.
• Male or Female.
• Capable of giving signed informed consent which includes compliance with the requirements and restrictions.

Exclusion Criteria:

• Subjects who have a known drug allergy or other contra-indication to ipratropium bromide.
• Known hypersensitivity to atropine or ipratropium bromide or any other known drug allergies that, in the opinion of the investigator or GlaxoSmithKline (GSK) Medical Monitor, contraindicates their participation.
• As a result of the medical history, physical examination or screening investigations, the physician responsible considers the subject unfit for the study.
• The subject is unable or unwilling to perform study assessments and procedures correctly.
• Subjects with a recognized co-existing respiratory disorder (other than ILD) that in the opinion of the investigator would confound the study outcomes.

Male or female subjects above 18 years of age with suspected ILD referred for TBCB for clinical reasons, as part of their diagnostic work up, will be included in this study.