abstract |
An active ingredient from the group of an antihistamine, a decongestant, an antitussive or anticholinergic is dissolved in a suitable solvent and added to a dispersion of tannic acid in water to form the tannate salt complex of the active ingredient. The active ingredient tannate salt complex without isolation or purification is then added to a liquid or semi-solid medium composed of thickening, suspending, coloring, sweetening and flavoring agents, with stirring. Thereafter, preservatives, pH-adjusting and anti-caking agents in a suitable solvent are mixed with the liquid or semi-solid medium to generate a therapeutic dosage form. |