Usefulness and limitations of taste sensors in the evaluation of palatability and taste-masking in oral dosage forms

Testing the disintegration and texture-related palatability predictions for orodispersible tablets using an instrumental tool coupled with multivariate analysis: Focus on process variables and analysis settings

Orodispersible tablets (ODTs) represent a growing category of dosage forms intended to increase the treatment acceptability for special groups of patients. ODTs are designed to rapidly disintegrate in the oral cavity and to be administered without water. In addition, ODTs are easy to manufacture using standard excipients and pharmaceutical equipment. This study adds to previously published research that developed an instrumental tool to predict oral disintegration and texture-related palatability of ODTs with different formulations. The current study aimed to challenge the predictive capacity of the models under variable process conditions. The studied process parameters with potential impact on the pharmaceutical properties, texture profiles, and palatability were the compression pressure, punch shape and diameter. Subsequently, for all the placebo and drug-loaded ODTs, the in vivo disintegration time and texture-related palatability were determined with healthy volunteers. Previously developed regression models were applied to predict the formulation's disintegration time and texture-related palatability characteristics of ODTs obtained under different experimental conditions. The influence of process variables on the predictive performance of the models was estimated by calculating the residuals as the difference between the predicted and observed values for the investigated response. Increasing the speed of the analyser`s probe from 0.01 mm/s to 0.02 mm/s led to an improved differentiation of the texture profiles. The in vivo disintegration time and texture-related palatability scores were only influenced by the mechanical resistance and the tablet shape. Lower score was observed for the larger diameter tablets (10 mm). Overall, the prediction of the disintegration time at 0.02 mm/s was more accurate, except for stronger tablets. The best prediction of texture-related palatability was achieved for the 10 mm tablets, tested at 0.01 mm/s speed. The same model achieved good predictions of the oral disintegration time for all API-loaded formulations, which confirmed the ability of the texture analysis to capture process-related variability. Drug loading decreased the predictive capacity of the texture-related palatability because of the taste effect.

Volatile Flavor Profile and Sensory Properties of Vegetable Soybean

The volatile flavor profiles and sensory properties of different vegetable soybean varieties popularized and cultivated in China for 20, 10, and 2 years (TW292, X3, and SX6, respectively) were investigated. Nutrient composition analysis revealed that TW292 had a high soluble protein and soluble sugar content but low fat content. The total free amino acid content (15.43 mg/g) and umami free amino acid content (6.08 mg/g) of SX6 were significantly higher (p < 0.05) than those of the other varieties. An electronic tongue effectively differentiated between the umami and sweetness characteristics of the vegetable soybeans. Differences in sensory evaluation results were mainly reflected in texture and taste. A total of 41 volatile compounds were identified through HS-SPME-GC-MS, and the main flavor compounds were 1-octen-3-ol, hexanal, (Z)-2-heptenal, 2-octene, nonanal, (Z)-2-decenal, and 3,5-octadien-2-one. However, the volatile composition of different vegetable soybean varieties exhibited large variability in type and relative contents. Considerable differences in nutritional, organoleptic, and aroma characteristics were found among different varieties. The results of this study will provide a good basis for the assessment and application of the major vegetable soybean varieties grown in China.

In Vivo and In Vitro Taste Assessment of Artesunate-Mefloquine, Praziquantel, and Benznidazole Drugs for Neglected Tropical Diseases and Pediatric Patients

The assessment of drug taste is crucial for pediatric treatments so that formulations can be developed to enhance their effectiveness. In this study, in vivo and in vitro methods were applied to evaluate the taste of tablets of three drugs administered to children without taste-masking excipients to treat tropical diseases, namely artesunate-mefloquine (ASMQ), praziquantel (PZQ), and benznidazole (BNZ). In the first method, a model of rat palatability was adapted with recirculation to ensure sample dispersion, and the data were analyzed using ANOVA (single factor, 95%). The taste assessment results (in vivo) indicated an aversion to the three medicines, denoted by the animals retracting themselves to the bottom of the box after the first contact with the drugs. For the placebo samples, the animals behaved normally, indicating that taste perception was acceptable. The second method was based on the in vitro analysis of capacitance data from a homemade impedimetric electronic tongue. Consistent with the in vivo taste assessment results, the data points obtained with PZQ, ASMQ, and BNZ were far away from those of their placebos in a map built with the multidimensional projection technique referred to as Interactive Document Mapping (IDMAP). A combined analysis of the results with the two methods allowed us to confirm the bitterness of the three drugs, also pointing to electronic tongues as a promising tool to replace in vivo palatability tests.

Formulation and evaluation of bitter taste-masked orally disintegrating tablets of high memantine hydrochloride loaded granules coated with polymer via layering technique

Orally disintegrating tablets (ODTs) improve patient adherence as they can easily disintegrate in the presence of small amount of saliva. However, the bitter taste of the active pharmaceutical ingredient in ODTs reduces patient compliance. The present study aimed to formulate bitter taste-masked ODTs containing high-dose of memantine hydrochloride (MTN) to achieve a balance between bitterness suppression and dissolution rate or disintegration time and mechanical strength. The high MTN-loaded granules were prepared using a fluidized bed granulator. Taste-masking granules coated with the selected polymer were prepared using the layering technique. Three ODTs, composed of granules coated with different polymers, were prepared. The ODT prepared using granules coated with enteric polymers showed the fastest collapse time (>20 s). Dissolution rates of ODTs composed of enteric polymers were reduced by 5 min compared with ODTs composed of non-coated or coated with water-insoluble polymer granules. X-ray computed tomography analysis revealed that low density distribution of ODTs with enteric polymer granules may result in faster disintegration time. Although ODT prepared using enteric polymers had the fastest collapse time, its change in membrane potential caused by adsorption (CPA), corresponding to aftertaste, was the lowest among formulations. This CPA value was lower than the bitterness threshold.

Similarity Evaluation on the Compound TCM Formulation "Huoling Shengji Granule" and Its Placebo by Intelligent Sensory Evaluation Technologies and the Human Sensory Evaluation Method Based on Critical Quality Attributes

To evaluate the similarity of Huoling Shengji granule (HLG) and its placebo at both granules and solution status, the innovative methods that consist of intelligent sensory evaluation technologies and human sensory evaluation methods were developed based on critical quality attributes (CQAs) of granule. The CQAs for traditional Chinese medicine (TCM) placebo granule were mainly divided into three categories: formulation attributes, visual attributes, and attributes of taste and smell. In this investigation, the novel intelligent sensory evaluation technologies including the physical property testing apparatus, computer vision system, color card, and electronic tongue (E-tongue) were employed for characterization of CQAs of HLG and its placebo. Meanwhile, human sensory evaluation by test panels was used to description the HLG and its placebo in terms of appearance, color, taste, and smell. On that basis, the similarity of placebo to CQAs of HLG was assessed by calculating the angle cosine values. The intelligent and human sensory evaluation results showed that the similarity values of HLG and its placebo about the CQAs at granule and solution status were all close to 1, which means that the two preparations have high similarities. In this study, the established similarity evaluation methods based on the CQAs were convenient and reliable, which can be utilized to evaluate the similarity of TCM granule and their placebo at granule and solution status, and demonstrated to be well applied in placebo-controlled trials.

The use of electronic tongue and sensory panel on taste evaluation of pediatric medicines: a systematic review

The palatability of medications is an essential factor for children's adherence to drug treatment. Several methods for drug taste assessment have been developed. The aim of this review is to explore the literature reports of the main methods for the evaluation of medicines taste, named electronic tongue (e-tongue, in vitro) and human sensory panel. A systematic search was performed up to March 2020 and a total of 88 articles were selected. The e-tongue (57.5%) has been more frequently described than the sensory panel (10.3%), while some articles (32.2%) used both techniques. 74.7% of the articles mentioned 'pediatric', 'paediatric' or 'children' in the text, but only 19.5% developed formulations targeting pediatric audience and sensory testing in children is rarely seen. The e-tongue has predominance of use in the taste evaluation of pediatric medicines probably since it is fast, easy to perform and risk free, besides presenting less imprecise data and no fatigue. The human panel is more realistic, despite its intrinsic variability. In this sense, it is proposed the use of e-tongue as a fast way to select the most promising sample(s) and, after that, the sensory panel should be applied in order to confirm the taste masking.

Taste Sensor: Electronic Tongue with Lipid Membranes

Taste is of five basic types, namely, sourness, saltiness, sweetness, bitterness and umami. In this review, we focus on a potentiometric taste sensor that we developed and fabricated using lipid polymer membranes. The taste sensor can measure the taste perceived by humans and is called an electronic tongue with global selectivity, which is the property to discriminate taste qualities and quantify them without discriminating each chemical substance. This property is similar to the gustatory system; hence, the taste sensor is a type of biomimetic device. In this paper, we first explain the sensing mechanism of the taste sensor, its application to beer evaluation and the measurement mechanism. Second, results recently obtained are introduced; i.e., the application of the senor to high-potency sweeteners and the improvement of the bitterness sensor are explained. Last, quantification of the bitterness-masking effect of high-potency sweeteners is explained using a regression analysis based on both the outputs of bitterness and sweetness sensors. The taste sensor provides a biomimetic method different from conventional analytical methods.

A donepezil/cyclodextrin complexation orodispersible film: Effect of cyclodextrin on taste-masking based on dynamic process and in vivo drug absorption

The aim of this study was to develop a palatable donepezil (DP) orodispersible film (ODF) to facilitate the swallowing process and investigate the effect of cyclodextrin on taste-masking based on dynamic process and in vivo drug absorption. Complexation of DP with hydroxypropyl-β-cyclodextrin (HP-β-CD) was applied to mask the bitter taste then the prepared complexes were incorporated into ODF using solvent casting method. The taste-masking efficiency was evaluated by e-tongue; meanwhile the pharmacokinetic behavior of DP/HP-β-CD ODF was investigated by in vivo study. Results showed the optimized film was more palatable than donepezil hydrochloride (DH) film and was bioequivalent with DH. The molecular mechanism was revealed by phase solubility study, Fourier-transform infrared spectrometer (FT-IR), Differential scanning calorimeter (DSC), X-ray diffraction (XRD) and molecular modeling. Taste-masking was attributed to the formation of DP/HP-β-CD which was due to moderate interaction between DP and HP-β-CD. The stability of DP/HP-β-CD was decreased because of the acid environment in stomach, which facilitated the absorption of DP. These results extended our understanding about the application of cyclodextrin complexation and provided guidance for the design of ODF especially for drugs with disgusting taste.

Comparative in vitro and in vivo taste assessment of liquid praziquantel formulations

The taste of pharmaceuticals strongly affects the compliance of patients. This study investigated the applicability of the electronic tongue and rodent brief-access taste aversion (BATA) model for the bitter compound praziquantel (PZQ) and taste masked liquid formulations for PZQ. In a comparative study maltodextrin (MD) Kleptose^® linecaps 17 was selected as an alternative taste masking agent to two cyclodextrins; hydroxypropyl-beta-cyclodextrin (HP-β-CD) and sulfobutyl ether-beta-cyclodextrin (SBE-β-CD). A phase solubility study showed the highest affinity and solubilization capabilities for SBE-β-CD over HP-β-CD and MD, suggesting the highest taste masking ability for SBE-β-CD. No reliable results were achieved for PZQ with the Insent electronic tongue. Thus this system was not used for further evaluation of solutions with MD and CDs to confirm the results of the solubility study. In contrast the BATA model demonstrated conclusive responses for the aversiveness of PZQ. The concentration of PZQ inhibiting 50% of water lick numbers (called IC₅₀ value) was 0.06mg/ml. In contrast to the phase solubility study, the MD enabled an equal taste masking effect in vivo in comparison to both CDs. Moreover HP-β-CD showed superior taste masking capabilities for PZQ compared to SBE-β-CD as the SBE-β-CD itself was less acceptable for the rodents than HP-β-CD. In conclusion, the BATA model was identified as a more efficient taste assessment tool for the pure PZQ and liquid formulations in contrast to the electronic tongue and the phase solubility study.