Gustatory Sensation Tests Research Articles

Phenylalanine-free taste-masked orodispersible tablets of fexofenadine hydrochloride: development, in vitro evaluation and in vivo estimation of the drug pharmacokinetics in healthy human volunteers

Context: Fexofenadine hydrochloride (FXD) is a slightly soluble, bitter-tasting, drug having an oral bioavailability of 35%. The maximum plasma concentration is reached 2.6 h (Tmax) post-dose.Objective: Developing taste-masked FXD orodispersible tablets (ODTs) to increase extent of drug absorption and reduce Tmax.Methods: Taste masking was achieved via solid dispersion (SD) with chitosan (CS) or sodium alginate (ALG). Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffraction were performed to identify physicochemical interactions and FXD crystallinity. Taste-masked FXD-ODTs were developed via addition of superdisintegrants (croscarmellose sodium or sodium starch glycolate, 5% and 10%, w/w) or sublimable agents (camphor, menthol or thymol; 10% and 20%, w/w) to FXD-SDs. ODTs were evaluated for weight variation, drug-content, friability, wetting, disintegration and drug release. Camphor-based (20%, w/w) FXD-ODT (F12) was optimized (F23) by incorporation of a more hydrophilic lubricant (Pruv®), visualized via scanning electron microscopy and evaluated for FXD pharmacokinetics in healthy volunteers relative to Allegra® tablets.Results: Based on gustatory sensation test, FXD–CS (1:1) and FXD–ALG (1:0.5) SDs were selected. Taste-masked FXD-ODTs had appropriate physicochemical properties. Drug release profiles of F23 and the phenylalanine-containing Allegra® ODT were similar (f2 = 96). Pores were observed following camphor sublimation. The pharmacokinetic studies proved F23 ability to increase extent of FXD absorption and reduce Tmax.

Bitterness evaluation of acidic pharmaceutical substances (NSAIDs) using a taste sensor.

The objective of this study was to evaluate an improved bitterness sensor which has been developed to allow the precise and sensitive prediction of the bitterness of acidic bitter pharmaceutical active ingredients, using as examples nine non-steroidal anti-inflammatory drugs (NSAIDs). The bitterness of the nine NSAIDs was measured using a multichannel taste-sensing system incorporating a bitterness sensor, C00, which has a membrane surface with high hydrophobicity, and was developed to allow an enhanced hydrophobic interaction with acidic bitter substances. The sourness intensities of the nine NSAIDs were also determined in gustatory sensation testing and by a taste sensor using a sourness-sensitive membrane, CA0. The 'Change in membrane Potential caused by Adsorption' (CPA) of sodium diclofenac and etodolac were also determined in the presence of increasing concentrations of tartaric acid using membrane C00. Multiple regression analysis performed on the data on bitterness intensity obtained using the taste sensor and in gustatory sensation testing showed that CPA values from C00 could be used to predict the bitterness of the NSAIDs. The derived equation was y = -0.0413 × CPA + 0.3164, where y represents the predicted bitterness intensity. There were concentration-dependent changes in the bitterness intensities of diclofenac sodium and etodolac without any change in their sourness intensities. For diclofenac sodium and etodolac, there was a good correlation between predicted and actual bitterness intensities in the presence of increasing concentrations of tartaric acid. The taste sensor may be useful for predicting the bitterness intensity of acidic bitter pharmaceutical active ingredients such as NSAIDs.

Evaluation of palatability of 10 commercial amlodipine orally disintegrating tablets by gustatory sensation testing, OD-mate as a new disintegration apparatus and the artificial taste sensor

The purpose of this study was to evaluate and compare the palatability of 10 formulations (the original manufacturer's formulation and nine generics) of amlodipine orally disintegrating tablets (ODTs) by means of human gustatory sensation testing, disintegration/dissolution testing and the evaluation of bitterness intensity using a taste sensor. Initially, the palatability, dissolution and bitterness intensity of the ODTs were evaluated in gustatory sensation tests. Second, the disintegration times of the ODTs were measured using the OD-mate, a newly developed apparatus for measuring the disintegration of ODTs, and lastly, the bitterness intensities were evaluated using an artificial taste sensor. Using factor analysis, the factors most affecting the palatability of amlodipine ODTs were found to be disintegration and taste. There was high correlation between the disintegration times of the 10 amlodipine ODTs estimated in human gustatory testing and those found using the OD-mate. The bitterness intensities of amlodipine ODTs 10, 20 and 30 s after starting the conventional brief dissolution test and the values determined by the taste sensor were highly correlated with the bitterness intensities determined in gustatory sensation testing. The OD-mate and the taste sensor may be useful for predicting the disintegration and bitterness intensity of amlodipine ODTs in the mouth.

Study of the Physicochemical Properties of Tulobuterol Dry Syrups Using Taste and Smell Sensors

The purpose of the present study was to evaluate the taste and smell of Tulobuterol Dry Syrup (TB-DS) in its original form (formulation A) and generic form (formulations B and C) by means of gustatory sensation tests and taste and smell sensors. In addition, the physicochemical properties of the syrups in a solid state were compared. Evaluation of sweetness with a powdered sample revealed significant differences between formulation A and formulation B and between formulation B and formulation C. In contrast, the results of principal component analysis (PCA) with a taste sensor revealed differences in principal component 1 (PC 1) among formulations A, B, and C. Smell sensor measurement of powdered samples revealed differences in products in terms of only PC 1, but these results were not related to the results of gustatory sensation testing with a smell sensor. Measurement of particle size distribution and scanning electron microscopy revealed differences in the particle diameter and particle surface shape for each product. Formulation B had the strongest absorption in the near-infrared spectrum, followed by formulation A and then formulation C. Accordingly, differences in preparations were presumably caused by variations in manufacturing specifications, such as types of additives and their content and coating methods used. In other words, the characteristics of each product were revealed by evaluation of their physical properties, sensing of taste and smell, and human gustatory sensation tests.

Taste Masking of Propiverine Hydrochloride by Conversion to Its Free Base

The aim of the present study was to mask the bitterness of propiverine hydrochloride (P-4) by converting it to propiverine free base. Fine granules comprising the free base, which was converted from P-4 by desalination, were prepared. By using Fourier transform infrared spectroscopy, thermogravimetry-differential thermal analysis, and powder X-ray diffraction spectra, we confirmed that P-4 had been converted into propiverine free base by desalination during the manufacturing process. Furthermore, the conversion into free base appeared to result in decreased solubility, and both the taste testing sensor and tasting volunteers determined that it masked the bitterness of P-4. On using the gustatory sensation test, the bitterness of the P-4 fine granules was confirmed to be weakened. The dissolution rate and bioavailability of fine granules of the free base were compared with tablets of P-4. The dissolution rate and bioavailability of the fine granules and tablets were almost the same. We successfully masked the taste of P-4 by converting it into free base using a manufacturing process that was suitable for commercial manufacturing.

Factors Affecting the Bitterness Intensities of Ten Commercial Formulations of Ambroxol

The bitterness of 10 different products with ambroxol as active ingredient, the original and nine generics, were evaluated by human gustatory sensation tests in which the tablets were kept in the mouth, with water, at 20 and 37°C. The products all showed different bitterness intensities. The original and some of the generic products had comparatively low bitterness intensities but some of the generic products had comparatively high bitterness intensities. The bitterness intensities of these 10 was found to be significantly correlated with both the disintegration time, as evaluated using the ODT-101 (a recently developed apparatus), and the drug concentration in dissolved medium, as measured in a conventional dissolution test. The bitterness threshold of ambroxol solution was found to increase when the temperature of the water with which the tablets were taken, was raised from 20 to 37°C. The equation was calculated to predict the bitterness intensity of ambroxol, a function based on temperature and the ambroxol concentration using data from a standard ambroxol solution at 4, 20 and 37°C. The bitterness intensities obtained for the 10 ambroxol formulations with water at 20 and 37°C, coincided with the bitterness values predicted by the equation.

Reduction of Bitterness of Antihistaminic Drugs by Complexation with β-Cyclodextrins

Reduction of bitterness of antihistaminic drugs by cyclodextrin (CyD) complexation was examined. The stability constant (Kc) of the 1:1 CyD inclusion complexes with antihistaminic drugs increased in the order of 2-hydroxypropyl-β-CyD (HP-β-CyD) ≈ β-CyD > γ-CyD > α-CyD for diphenhydramine and epinastine, and HP-β-CyD ≈ β-CyD > α-CyD > γ-CyD for hydroxyzine, cetirizine, and dl-chlorpheniramine. The inclusion complexes inhibited the adsorption of antihistaminic drugs to lipid membrane using liposomes, as the magnitude of Kc increased. From human gustatory sensation tests, β-CyD and HP-β-CyD potently suppressed the bitterness of antihistaminic drugs in a dose-dependent manner. Further, an artificial taste sensor analysis revealed that β-CyD and HP-β-CyD inhibited the bitterness of antihistaminic drugs in solution. The results suggest that CyDs suppress the bitterness of antihistaminic drugs in solutions through the formation of inclusion complexes. These results may provide useful information for masking or elimination of bitterness of drugs using CyDs.

Influence of Swallowing Aids on the Adsorption and Palatability of Kremezin

The purpose of this study was to evaluate the effect of three swallowing aids on the adsorbent properties and palatability of a mixture of the oral charcoal adsorbent, Kremezin®. None of the swallowing aids had any effect on the adsorption of indole by Kremezin®, either in vitro and in vivo. In gustatory sensation tests of the palatability of the swallowing aids with Kremezin®, 14 items were evaluated according to the semantic differential (SD) method. Factor analysis of the results identified two main factors 'Remaining after removing from mouth' and 'Sense of holding in mouth' as predominantly determining the palatability. The swallowing aid with the highest viscosity allowed the best dispersion of Kremezin®, and also improved the palatability of Kremezin® the most.

Palatable reconstitutable dry suspension of artemether for flexible pediatric dosing using cyclodextrin inclusion complexation

The present research was conducted to investigate the inclusion complexation of artemether (ARM) with beta-cyclodextrin (CD) with the aim of masking the bitterness along with improving the drug release and preparing a stable palatable formulation of ARM especially for pediatrics. A physical mixture and kneaded system were prepared to study the inclusion complexation. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on drug release. Reconstitutable dry suspension was evaluated for angle of repose, sedimentation characterization and pH. In vitro drug release studies for physical mixture and kneaded system were performed at pH, 1.2 and 6.8. Bitterness score was evaluated using gustatory sensation test. The FTIR, DSC and XRPD studies indicated inclusion complexation in physical mixture and kneaded system. In addition, physical mixture and kneaded system exhibited improved drug release at pH, 1.2 and 6.8. To formulate palatable reconstitutable dry suspension of ARM, the 1:20M physical mixture was selected based on bitterness score. Reconstitutable dry suspension prepared using physical mixture (DS4), showed complete bitter taste masking, good flowability and ease of redispersibility. Taste evaluation of reconstitutable dry suspension in human volunteers rated tasteless with a score of 0 to DS4 and 3 to DS5 (reconstitutable dry suspension prepared using pure ARM). This conclusively demonstrated a stable and palatable reconstitutable dry suspension of ARM using CD inclusion complexation for flexible pediatric dosing.

Evaluation of the bitterness of antibiotics using a taste sensor.

The bitterness of nine commercial antibiotics (clarithromycin, erythromycin, cefdinil, doxycycline, vancomycin, tetracycline, minocycline, oxytetracycline and bacampicillin) was evaluated in human gustatory sensation tests with nine volunteers. The bitterness of 0.1-0.3 mM solutions (or suspensions in the case of clarithromycin) of the antibiotics was then measured using an artificial multichannel taste sensor. In the sensor measurements, three variables were used to predict estimated bitterness in single and multiple regression analysis and principal component analysis: sensor output as relative value (R), the change of membrane potential caused by adsorption (C) and C/R. Particularly good correlation was obtained between obtained bitterness scores and predicted scores using C from channel 2 of the sensor (r2=0.870, P<0.005) and C/R values for channels 2 and 3 (r2=0.947, P<0.005). The taste sensor was also successful in assessing the bitterness intensity of clarithromycin powder suspensions of various concentrations. Clarithromycin has a low aqueous solubility but is the most bitter of the nine antibiotics. Sensory data from channel 3 of the sensor predicted the bitterness of clarithromycin powder suspensions and their filtered solutions well. Finally, the bitterness intensity of a commercial clarithromycin dry syrup product (Clarith dry syrup, Taisho Pharmaceutical Co. Ltd, Tokyo, Japan) was evaluated in gustatory sensation tests and using the taste sensor. In Clarith dry syrup the drug is coated with aminoalkyl methacrylate polymer using a spray congealing method. The taste sensor results confirmed that the polymer was successful in almost completely masking the bitter taste of the dry syrup product.

Effect of chitosan crosslinking on bitterness of artemether using response surface methodology

This work examines the influence of various process parameters on artemether entrapped in crosslinked chitosan microparticles for masking bitterness. A central composite design was used to optimize the experimental conditions for bitterness masking. Critical parameters such as the amounts of artemether, chitosan and crosslinking agent have been studied to evaluate how they affect responses such as incorporation efficiency, particle size and drug release at pH 6.8. The desirability function approach has been used to find the best compromise between the experimental results. The optimized microparticles were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. Bitterness score was evaluated by human gustatory sensation test. Multiple linear regression analysis revealed that the crosslinking of chitosan significantly affects incorporation efficiency, particle size and drug release at pH 6.8. The bitterness score of microparticles was decreased to 0, compared with 3+ for pure artemether. The proposed method completed masked the bitter taste of artemether.

Formulation and evaluation of primaquine phosphate taste-masked rapidly disintegrating tablet

Abstract This work investigates the complete bitter-taste-masking of primaquine phosphate (PRM) using a solid dispersion with mono ammonium glycyrrhyzinate pentahydrate (GLY). This work also describes the preparation of rapidly disintegrating tablets (RDTs) of PRM by a direct compression method using superdisintegrant, croscarmellose sodium. A solid dispersion was prepared by the solvent evaporation method. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on dissolution. In-vitro drug release studies were performed for RDTs at both pH 1.2 and 6.8. Bitterness score was evaluated using a human gustatory sensation test. FTIR spectroscopy and DSC showed no interaction of PRM in GLY solid dispersion. RDTs prepared from solid dispersion showed complete bitter-taste-masking of PRM. RDTs containing solid dispersion exhibited a better dissolution profile, at both pH 1.2 and 6.8, than pure PRM. Thus, the solid dispersion technique can be successfully used for complete bitter taste masking of PRM.

Bitterness Suppression of the Kampo Medicine 'Orengedokuto' Using Flavoured Jellies

The purpose of this study was to evaluate the effect of various flavoured jellies on the palatability and bitterness of the Kampo medicine 'Orengedokuto', using human gustatory sensation testing. In the gustatory sensation test, eight items were evaluated according to the semantic differential (SD) method and four taste intensities (sweetness, astringency, sourness, and bitterness) were determined. Factor analysis of the results identified two main factors 'Disagreeable taste' and 'Agreeable taste and odour' as predominantly determining the palatability of Orengedokuto. To investigate the influence of jelly odour, evoked images were obtained for five fundamental tastes after smelling jellies. The inhibitory effect of the jelly odour on the bitterness of Orengedokuto was found to be small. When the influence of the various jellies on the disagreeable taste of Orengedokuto was investigated, the bitterness intensities of Orengedokuto mixed with chocolate or strawberry-chocolate jelly were found to be significantly lower than the bitterness of the control. The bitterness intensity of Orengedokuto was found to be significantly and negatively correlated with sweetness intensity using simple linear regression analysis. These results suggest that the sweetness intensity of various jellies inhibits the bitterness intensity of Orengedokuto.

Development of Taste Masked Fast Disintegrating Films of Levocetirizine Dihydrochloride for Oral Use

Fast disintegrating films of levocetirizine dihydrochloride useful for the treatment of acute allergic rhinitis and chronic urticaria have been developed by using the taste masking ability of cyclodextrins. The fast disintegrating films were prepared by solvent casting method. The films contained water-soluble polymers such as Kollicoat IR or pullulan, aspartame and sucralose as sweeteners and pre-gelatinized starch as disintegrant. Levocetirizine dihydrochloride was incorporated into these films by in-situ complex formation with hydroxy propyl beta-cyclodextrin. The optimized films were evaluated for weight variation, film thickness, folding endurance, tackiness, tensile strength, assay, content uniformity, in vitro disintegration and dissolution, in vivo disintegration and taste masking ability by human gustatory sensation test. Results revealed that the organoleptic properties of levocetirizine dihydrochloride were improved by complexation with hydroxy propyl beta-cyclodextrin and the complex could be successfully formulated into a fast disintegrating film.

A New Method for Evaluating the Bitterness of Medicines in Development Using a Taste Sensor and a Disintegration Testing Apparatus

The purpose of this study was to demonstrate the usefulness and wide applicability of a taste sensor and a new disintegration testing apparatus in the development and/or evaluation of orally disintegrating tablets (ODTs). In this paper, we described methods for the effective utilization of a taste sensor in the development of a new medicine. First we predicted the taste of propiverine hydrochloride, a model drug substance whose taste is unknown, using a taste sensor. Then we screened masking agents for their ability to suppress the bitterness of propiverine hydrochloride, and manufactured ODTs of propiverine hydrochloride with various masking agents. The tastes of these ODTs were then evaluated in chronological order by combining the taste sensor with the new disintegration testing apparatus, ODT-101, to resemble the oral cavity. As a result, we were able to evaluate the taste of propiverine hydrochloride and the effectiveness of various masking agents in ODTs. The result using this combination of taste sensor and ODT-101 shows good agreement with the results of human gustatory sensation testing, thus demonstrating the usefulness and applicability of the taste sensor and disintegration testing apparatus, ODT-101, in the development of new medicine.

Enzymatic synthesis of gentiooligosaccharides by transglycosylation with β-glycosidases from Penicillium multicolor

A crude enzyme preparation from Penicillium multicolor efficiently produced mainly gentiotriose to gentiopentaose (d.p. 3–5) by transglycosylation using a high concentration of gentiobiose as the substrate. The resulting gentiotriose was examined in a gustatory sensation test using human volunteers, and was determined to have one-fifth of the bitterness of gentiobiose. The crude enzyme preparation was analyzed by chromatography to determine the enzyme responsible for formation of the gentiooligosaccharides. The transglycosylation was shown to take place in two stages by a combination of β-glucosidase and β-(1→6)-glucanase. In the initial stage, which was the rate-limiting step in the overall process, β-glucosidase produced mainly gentiotriose from gentiobiose. In the second step, β-(1→6)-glucanase acted on the resulting gentiotriose, which served as both donor and acceptor, to produce a series of gentiooligosaccharides (d.p. 4–9) by transglycosylation.

Influence of Chitosan Crosslinking on Bitterness of Mefloquine Hydrochloride Microparticles Using Central Composite Design

The present work examines the influence of various process and product parameters on mefloquine hydrochloride (MFL) entrapped in crosslinked chitosan microparticles for masking the bitterness. A central composite design (CCD) was employed to investigate the effect of three process and product variables, namely amount of MFL, chitosan and sodium hydroxide (crosslinking agent) on the incorporation efficiency, particle size, drug release at pH 6.8 and bitterness score. The microparticles were prepared by ionotropic gelation method, with a hardening time of 60 min. The optimum condition for process and product variables was evaluated using desirability function. The model is further cross validated for bias. The optimized microparticles were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. Bitterness score was evaluated by human gustatory sensation test. Multiple linear regression analysis revealed that the crosslinking of chitosan significantly affects incorporation efficiency, particle size, drug release and bitterness score. The bitterness score was decreased to zero compared to 3+ of pure MFL. It can be inferred that the proposed methodology can be used to prepare MFL microparticles for bitter taste masking. © 2008 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:690–703, 2009

Famotidine Orally Disintegrating Tablets: Bitterness Comparison of Original and Generic Products

The purpose of the present study was to compare the palatability of the original and eight generic versions of famotidine orally disintegrating tablets by means of human gustatory sensation tests, a comparison of the release profiles, and using an automated taste sensor, the alpha-Astree Electronic Tongue. In the gustatory sensation test, the original product (Gaster D, 10 mg) showed the lowest bitterness intensity. Among the eight generic products tested, the variance in the sweetness intensity was not great, but there were large variances in the intensity of bitterness, some of the generic products being significantly more bitter than that of the original product. On the other hand, some generic products show similar bitterness level as the original product. In a study of release profiles, the original product had the lowest release rates of both famotidine and aspartame; in comparison, some of the generic products had high release rates of famotidine and aspartame, even in the initial stages. Whereas some generic products had low release rates of famotidine and aspartame. Finally, sample solutions were analysed using the taste sensor. There was a good correlation between the taste predicted by principal component analysis and the Euclidean distance obtained by the taste sensor, and bitterness intensities obtained in the human gustatory tests.

Formulation and evaluation of primaquine phosphate taste-masked rapidly disintegrating tablet

This work investigates the complete bitter-taste-masking of primaquine phosphate (PRM) using a solid dispersion with mono ammonium glycyrrhyzinate pentahydrate (GLY). This work also describes the preparation of rapidly disintegrating tablets (RDTs) of PRM by a direct compression method using superdisintegrant, croscarmellose sodium. A solid dispersion was prepared by the solvent evaporation method. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on dissolution. In-vitro drug release studies were performed for RDTs at both pH 1.2 and 6.8. Bitterness score was evaluated using a human gustatory sensation test. FTIR spectroscopy and DSC showed no interaction of PRM in GLY solid dispersion. RDTs prepared from solid dispersion showed complete bitter-taste-masking of PRM. RDTs containing solid dispersion exhibited a better dissolution profile, at both pH 1.2 and 6.8, than pure PRM. Thus, the solid dispersion technique can be successfully used for complete bitter taste masking of PRM.

Formulation and Evaluation of Taste Masked Oral Reconstitutable Suspension of Primaquine Phosphate

The purpose of this research was to mask the intensely bitter taste of primaquine phosphate (PRM) and to formulate suspension powder (cachets) of the taste masked drug. Taste masking was done using beta-cyclodextrin. To characterize and formulate taste masked cachets of PRM, the 1:25 M physical mixture was selected based on bitterness score. Phase solubility studies, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray powder diffraction (XRPD) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on dissolution. Cachets were evaluated for angle of repose, sedimentation characterization and pH. In vitro drug release studies for physical mixture and kneaded system were performed at pH, 1.2 and 6.8. Bitterness score was evaluated using gustatory sensation test. Phase solubility studies showed weak interaction between PRM and CD. The FTIR, DSC and XRPD studies indicated inclusion complexation in physical mixture and kneaded system. In addition, kneaded system and physical mixture exhibited better drug release at pH 1.2 and negligible effect at pH 6.8. Cachets prepared using physical mixture, (DS24), showed complete bitter taste masking and easy redispersibility. Taste evaluation of cachets in human volunteers rated tasteless with a score of 0 to DS24 and 3 to DS25. Thus, results conclusively demonstrated successful taste masking and formulation of cachets with taste masked drug.