1. Signed Informed Consent, according to local guidelines and regulation.
2. Male and female adults (>18 years old).
3. Mechanically ventilated (invasive) patients with PaO2/FIO2 ratio ≤200 in the presence of PEEP of greater than or equal to 5 cmH20.
4. Respiratory failure not fully explained by cardiac failure or fluid overload (if acute Congestive Heart Failure exacerbation is identified as part of the clinical picture this should be addressed effectively and as soon as possible before the patient can be enrolled).
5. Bilateral radiologic opacities consistent with pulmonary edema on the frontal chest x-ray (CXR), or bilateral ground glass opacities on a chest computerized tomography (CT) scan.
6. Less than or equal to 48 hours from fulfilling above ARDS criteria.
7. Less than or equal to 7 days from hospital admission.
8. Females of child-bearing potential who are sexually active must be willing not to get pregnant within 30 days after the last Investigational Medicinal Product (IMP) dose and must agree to at least one of the following reliable methods of contraception:

Female participants of non-child-bearing potential or in post-menopausal status for at least 1 year will be admitted. For all female subjects with child-bearing potential, pregnancy test result must be negative before first drug intake.

1. Moderate-severe chronic hepatic disease (as verified by relevant history, imaging, if pre-existent, and Child-Pugh score B-C).
2. Severe chronic renal dysfunction: eGFR (MDRD) < 30 mL/min/1.73m2 or End Stage Renal Disease on renal replacement therapy.
3. Participation in another interventional clinical trial.
4. Patients that are clinically determined to have a high likelihood of death within the next 24 hours based on PI's estimation.
5. Evidence of anoxic brain injury
6. Currently receiving ECMO or high frequency oscillatory ventilation.
7. Anticipated extubation within 24 hours of enrollment.
8. Active malignancy (with the exception of non-melanotic skin cancers).
9. Hemodynamic instability (>30% increase in vasopressor in the last 6 hours or norepinephrine > 0.5 mcg/Kg/min).
10. Evidence of gastrointestinal (GI) dysmotility e.g., due to acute pancreatitis or immediate post-op state, as demonstrated by persistent gastric distention, enteral feeding intolerability and/or persistent gastric residuals >500 ml).
11. Anticipated discharge from the hospital or transfer to another hospital within 72 hours of screening.
12. Decision to withhold or withdraw life-sustaining treatment (patients may still be eligible however if they are committed to full support except cardiopulmonary resuscitation if cardiac arrest occurs).
13. History of:

a) Documented allergy/hypersensitivity to more than one medication belonging to the class of sulfonamides, such as sulfamethazine, sulfamethoxazole, sulfasalazine, nimesulide or celecoxib (hypersensitivity to sulphanilamide antibiotics alone, e.g., sulfamethoxazole does not qualify for exclusion), and to the study product and/or its excipients.

b) Lactase deficiency, galactosemia or glucose-galactose malabsorption.

c) History of GI bleeding or perforation due to previous Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) therapy or recurrent peptic ulcer/haemorrhage.

d) Hypersensitive to ibuprofen.

1. Active bleeding (excluding menses) or bleeding diathesis including patients on chronically high doses of NSAIDs.
2. Pregnant or lactating women.
3. Women of childbearing potential and fertile men who do not agree to use at least one primary form of contraception during the study and up to 30 days after the last IMP dose.