The present invention relates to a per oral, oral, or intranasal pharmaceutical mucoretentive, aqueous liquid composition comprising from about 2% to about 50%, by weight of the composition, of colloidal particles of silica, titanium dioxide, clay, and mixtures thereof and a safe and effective amount of a pharmaceutical active selected from the group consisting of analgesics, decongestants, expectorants, antitussives, antihistamines, sensory agents, gastrointestinal agents, and mixtures thereof; wherein the composition has a sedimentation volume ratio of greater than about 0.90 and wherein the triggered viscosity ratio of the composition is at least about 1.2. The present invention further relates to a method of coating the alimentary canal or nasal mucosa, in particular to a method of preventing or treating symptoms of upper respiratory tract infections or upper respiratory tract tissue irritation or damage, by administering a safe and effective amount of the above composition.