The pharmaceutical formulations of the invention for masking the odor from the sulfur-containing active agent comprise at least one sulfur-containing active agent, an effective amount of at least one flavoring agent. Any flavoring agent or combinations of flavoring agents may be used in the pharmaceutical formulation of the invention. The flavoring agent may be natural flavors, natural fruit flavors, artificial flavors, and mixtures thereof. The pharmaceutical formulation may contain an artificial sweetener, a natural sweetener or mixtures thereof. The pharmaceutical formulations are provided in liquid dosage form or a dry powder dosage form for reconstitution in water. Stabilizer added as one of expicients can extend the stability of the pharmaceutical formulation liquid dosage form for a period of at least 30 days when the formulation is stored below room temperature. The pharmaceutical formulations of the invention are palatable and particularly useful for the administration of sulfur-containing drugs to very small children that are in need of such medications. Methods of forming a liquid dosage form of pharmaceutical formulation by adding water to the dry powder form, methods to prepare an odor-masking pharmaceutical formulation and methods for treating lead poisoning or Wilson's disease using the odor-masking pharmaceutical formulation are also provided.