The purpose of this study is to evaluate the clinical efficacy, the safety and acceptability of three new oral sprays with a reference oral spray in the relief of drug-induced xerostomia associated with hyposialia, i.e. dryness of the mouth induced by a decrease of salivation (hyposialia) induced by chronic drug intake.

Inclusion Criteria:

• Male and female subjects,
• Adult subjects (≥18 years) taking drug(s) causing salivary hypofunction / xerostomia, for at least 1 week prior to study initiation and expected to continue without change during study
• Subjects with a complaint of dry mouth as assessed by a response of 40mm or greater on item "Rate the dryness of your mouth" of the Dry Mouth Visual Analogue Scale (VAS) questions. (The VAS limits will be 0 representing normal [i.e. no dry mouth symptoms] and 100 representing "the worst imaginable" dry mouth symptoms). This score should also be met before the 1st product application, on P1 D1.
• Documented hyposalivation with test of resting saliva weight absorbed ≤ 0.5g/5 min at baseline

Exclusion Criteria:

• Presence of disorders (bucco-dental disease, history of major medical/psychiatric illness or surgery, ... ) which, in the judgement of the investigator, may interfere with study implementation and/or study parameter assessment(s).
• Sjögren syndrome and related autoimmune diseases,
• Other medical causes of xerostomia (oral candidiasis).
• History of head and neck irradiation and cancer chemotherapy
• History of hypersensitivity to any of the components of the investigational products,
• History or current excessive use of alcohol,
• History of drug addiction,
• Presence of treatments for their dry mouth within 7 days prior to inclusion into the study