Formulation of poorly water-soluble drugs in lipid nanocarriers: a suitable approach for taste masking or bitter-taste enhancing?

Scholten, Julia; Pein-Hackelbusch, Miriam; Sokolowsky, Martina; Park, Julien; Steiner, Denise

Abstract

The taste of a drug formulation, especially of orodispersible and liquid dosage forms, is of crucial importance due to its direct contact with the human taste buds. In order to achieve high patient acceptance with these formulations, drugs with an unpleasant, predominantly bitter taste have to be masked. One strategy for masking taste particularly suitable for lipophilic drugs is to dissolve the drug molecules in lipid carrier systems, such as nanoemulsions. Although this strategy has often proven effective as a formulation strategy for improving bioavailability and masking an unpleasant taste, our study indicates that embedding the three poorly watersoluble model drugs fenofibrate, simvastatin, and naproxen in nanoemulsions led to newly created or increased bitterness compared to the non-formulated drug powders. We proved this using both an analytical taste sensor system, specifically an electronic tongue (e-tongue), and a sensory study with a human taste panel. Hereby, complete agreement between the e-tongue measurements and the sensory study was found despite the non-ionic character of fenofibrate and simvastatin. We hypothesize that the changed bitter taste impressions were due to the location of the drug molecules at the oil/water interfaces, which resulted in an increased bitter taste intensity and prolonged duration of the bitter taste. In summary, the study shows that incorporating drugs into lipid nanocarriers tended to worsen the taste rather than mask it.