Comparison of Bitterness Intensity between Prednisolone and Quinine in a Human Sensory Test Indicated Individual Differences in Bitter-Taste Perception

Abstract

Prednisolone is a frequently prescribed steroid with a bitter, unpalatable taste that can result in treatment refusal. Oral suspensions or powder dosage forms are often prescribed, particularly to pediatric patients, as they improve swallowability and ease of dose adjustment. Consequently, the bitterness of prednisolone is more apparent in these dosage forms. Few studies have investigated prednisolone’s bitterness. Thus, in this study, 50 adults evaluated the bitterness of prednisolone using the generalized Labeled Magnitude Scale (gLMS), in comparison with quinine, a standard bitter substance. Overall, prednisolone-saturated solution demonstrated the same extent (mean gLMS score: 46.8) of bitterness as 1 mM quinine solution (mean gLMS score: 40.1). Additionally, large individual differences were observed in the perception of the bitterness of prednisolone and quinine. Perceived flavors of some drugs are reportedly associated with bitter-taste receptor (TAS2Rs) polymorphisms. Therefore, we investigated the relationship between subjects’ genetic polymorphisms of TAS2R19, 38, and 46, and their sensitivity to bitterness. Although a relationship between TAS2R19 polymorphisms and the perception of quinine bitterness was observed, no significant relationship was found between the perceived bitterness of prednisolone and the investigated genes. Ultimately, the results show that despite individual differences among subjects, the cause of prednisolone’s strong bitterness is yet to be elucidated.

Critical View on the Qualification of Electronic Tongues Regarding Their Performance in the Development of Peroral Drug Formulations with Bitter Ingredients

“…Unfortunately, the authors were unable to find human threshold data for ranitidine HCl and prednisolone sodium. Indeed, publications can be found dealing with the taste intensities of, e.g., prednisolone [119] or ranitidine hydrochloride [120] compared to other drugs. However, for comparing the results of different experimental studies, the molecules should be the same (only comparing the same salts), and information about identified thresholds is required.…”

Sex Differences in the Bitterness Perception of an Aromatic Myrtle Bitter Liqueur and Bitter Compounds

“…Indeed, several herbs rich in bitter chemicals are often used in traditional Chinese and Ayurveda medicines for their beneficial properties [1,3,5,6]. The receptors for bitter taste are called taste 2 receptors (TAS2Rs or T2Rs) and are a subfamily of G proteincoupled Receptors (GPCRs) on the taste bud cells of the tongue and oral cavity [1,3,5,7,8]. Bitter taste receptors, TAS2Rs, expressed in extraoral tissues may also be responsible for some physiological effects exerted by bitter compounds and are thus considered potential drug targets for the treatment of several diseases and disorders [5,8,9].…”

“…Bitter taste receptors, TAS2Rs, expressed in extraoral tissues may also be responsible for some physiological effects exerted by bitter compounds and are thus considered potential drug targets for the treatment of several diseases and disorders [5,8,9]. The consumer's perception of bitter taste is a key factor in the acceptability and success of foods and drugs; therefore, food/pharmaceutical industries aim to mask or minimize bitterness to increase the acceptance of food products and avoid treatment refusal [2,4,6,7]. However, bitter substances can be well tolerated, and certain bitter foods (chocolate, broccoli, and whole wheat bread) and beverages (coffee and tea) are known to be safe for consumption [1,2,4].…”

“…Gustatory perception of the bitter taste is a promising area of study because of its role in food choices, feeding behavior, and food's perceived healthiness [4,[17][18][19]. Many studies are focused on the investigation of the genetic [1,2,7,9,17] and age [17][18][19] differences regarding bitterness perception; however, there is still limited and heterogeneous information on the influence of sex on bitter taste perception [7,[17][18][19]. The knowledge of sex differences in bitter taste acuity has potential applications in precision nutrition/medicine [18,20].…”

“…The knowledge of sex differences in bitter taste acuity has potential applications in precision nutrition/medicine [18,20]. Moreover, strategies are currently required to successfully reduce/mask bitterness in food/pharmaceutical products and increase their acceptance [4,6,7]. There is a great interest in the dietary use of aromatic herbs and spices for their ability to impart distinctive flavorings to food products, contemporaneously increasing their nutritional value and positively affecting human health [21].…”