{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T07:08:28Z","timestamp":1778569708571,"version":"3.51.4"},"reference-count":36,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2017,11,4]],"date-time":"2017-11-04T00:00:00Z","timestamp":1509753600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper reports the improvement of a bitterness sensor based on a lipid polymer membrane consisting of phosphoric acid di-n-decyl ester (PADE) as a lipid and bis(1-butylpentyl) adipate (BBPA) and tributyl o-acetylcitrate (TBAC) as plasticizers. Although the commercialized bitterness sensor (BT0) has high sensitivity and selectivity to the bitterness of medicines, the sensor response gradually decreases to almost zero after two years at room temperature and humidity in a laboratory. To reveal the reason for the deterioration of the response, we investigated sensor membranes by measuring the membrane potential, contact angle, and adsorption amount, as well as by performing gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS\/MS). We found that the change in the surface charge density caused by the hydrolysis of TBAC led to the deterioration of the response. The acidic environment generated by PADE promoted TBAC hydrolysis. Finally, we succeeded in fabricating a new membrane for sensing the bitterness of medicines with higher durability and sensitivity by adjusting the proportions of the lipid and plasticizers.<\/jats:p>","DOI":"10.3390\/s17112541","type":"journal-article","created":{"date-parts":[[2017,11,6]],"date-time":"2017-11-06T11:39:38Z","timestamp":1509968378000},"page":"2541","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Improved Durability and Sensitivity of Bitterness-Sensing Membrane for Medicines"],"prefix":"10.3390","volume":"17","author":[{"given":"Xiao","family":"Wu","sequence":"first","affiliation":[{"name":"Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hideya","family":"Onitake","sequence":"additional","affiliation":[{"name":"Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhiqin","family":"Huang","sequence":"additional","affiliation":[{"name":"Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takeshi","family":"Shiino","sequence":"additional","affiliation":[{"name":"Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yusuke","family":"Tahara","sequence":"additional","affiliation":[{"name":"Research and Development Center for Taste and Odor Sensing, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rui","family":"Yatabe","sequence":"additional","affiliation":[{"name":"Research and Development Center for Taste and Odor Sensing, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hidekazu","family":"Ikezaki","sequence":"additional","affiliation":[{"name":"Intelligent Sensor Technology, Inc., 5-1-1 Onna, Atsugi-shi, Kanagawa 243-0032, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kiyoshi","family":"Toko","sequence":"additional","affiliation":[{"name":"Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"},{"name":"Research and Development Center for Taste and Odor Sensing, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,11,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1248\/yakushi.130.81","article-title":"Preparation of orally disintegrating tablets with taste-masking function: Masking effect in granules prepared with correctives using the dry granulation method and evaluation of tablets prepared using the taste-masked granules","volume":"130","author":"Kawano","year":"2010","journal-title":"Yakugaku Zasshi"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.drudis.2007.01.010","article-title":"The latest trends in the taste assessment of pharmaceuticals","volume":"12","author":"Anand","year":"2007","journal-title":"Drug Discov. 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