Masking Offensive Odor of a Pediatric Oral Solution


The client was reformulating a pediatric powder for oral solution (POS) drug product to improve palatability as part of a lifecycle management program. Senopsys’ initial taste assessment revealed that the API was characterized by strong intensity “sulfidy” (overcooked vegetative) aromatics and weaker but patient-perceptible bitterness and sourness. A sweetener system was developed that effectively balanced and reduced the perception of the bitterness and sourness. The remaining challenge was to ameliorate the strong, repugnant odor of the API.

Senopsys Approach:  Senopsys applied a sensory-directed headspace evaluation approach adapted from the flavor and fragrance industries to guide the “odor masking” effort. Blends of aroma chemicals (“flavors”) were separately added to sweetened API solutions, mixed and allowed to equilibrate at room temperature in sealed containers. Senopsys’ trained sensory panelists evaluated the headspace aroma of the samples for the intensity of the sulfidy aromatics, using the Flavor Profile intensity scale. Based on the panelists’ feedback, custom blends of aroma chemicals were compounded by the flavor chemist and evaluated by the panelists in an iterative fashion.

Results: Following the sensory-directed formulation approach, a series of palatable prototype formulations were developed. The resulting sweetener system reduced the API bitterness and sourness. The custom blends of aroma chemicals were effective at blending with and reducing the perception of the “sulfidy” aromatics to below patient-perceptible levels (<1).