Development of oral taste masked diclofenac formulations using a taste sensing system

To achieve patient compliance, organoleptic aspects of drug substances play a key role in the development of oral pharmaceutical preparations. In this study, the ability of an electronic tongue to help in selecting a drug candidate and rationalize the development of oral taste masked formulations was evaluated. As drug, diclofenac, in the form of acid, sodium salt and potassium salt, was used. The taste sensing system Insent TS-5000Z was capable of differentiating diclofenac acid from its salts; and also distinguishing sodium and potassium salts eliciting similar taste modalities. Differences between qualities and intensities of sensor responses were mainly attributed to the different cations. Fewer taste and aftertaste stimuli were recorded for diclofenac acid. Based on this screening, the acid form was selected to formulate different diclofenac oral taste masked preparations further evaluated using electronic tongue data by comparing formulation prototypes against corresponding placebos. Output information demonstrated the ability of the taste sensors to detect and discriminate different formulation concepts and taste masking strategies. Comparative dissolution studies showed insufficient discrimination of formulation prototypes. Supported by these results, the electronic tongue proved to be a valuable additional tool for assessing and predicting the taste of active pharmaceutical ingredients in the early development stage.