The effects of four, commercial ceruminolytic agents on the middle ear.

Four, commercially available ceruminolytic agents and physiological saline were screened for ototoxic and inflammatory reactions on the middle ear mucosae of guinea pigs (n = 38) and dogs (n = 24). Each solution was injected transtympanically in anesthetized animals. The effects were assessed by brain stem auditory evoked response (BAER) tests to evaluate hearing function and by histological examination of the middle ear structures. Varying degrees of hearing loss and inflammation were observed in some guinea pigs and dogs treated with solutions A, C, and D, whereas no abnormal finding was associated with solution B or saline.