excipient
noun
ex·cip·i·ent ik-ˈsi-pē-ənt 
: a usually inert substance (such as gum arabic or starch) that forms a vehicle (as for a drug)
Example Sentences
Recent Examples on the Web The lipid excipient surrounds and protects the active ingredient in the vaccine. 
Laura Cooper, WSJ, 11 Dec. 2021 Between 2015 to 2019, health-care professionals, patients, and manufacturers filed nearly 2,500 reports to the FDA about an adverse reaction to an excipient. Popular Science, 15 Sep. 2020 But their problems are a bit of a medical mystery, because Merck hasn't changed the active ingredient in Levothyrox; what's new are the excipients, ingredients that help stabilize and bulk up the drug. Yves Sciama, Science | AAAS, 27 Sep. 2017 The new version contains mannitol and citric acid—both innocuous and widely used as excipients—instead of lactose. Yves Sciama, Science | AAAS, 27 Sep. 2017
Laura Cooper, WSJ, 11 Dec. 2021 Between 2015 to 2019, health-care professionals, patients, and manufacturers filed nearly 2,500 reports to the FDA about an adverse reaction to an excipient. Popular Science, 15 Sep. 2020 But their problems are a bit of a medical mystery, because Merck hasn't changed the active ingredient in Levothyrox; what's new are the excipients, ingredients that help stabilize and bulk up the drug. Yves Sciama, Science | AAAS, 27 Sep. 2017 The new version contains mannitol and citric acid—both innocuous and widely used as excipients—instead of lactose. Yves Sciama, Science | AAAS, 27 Sep. 2017 Word History
Etymology
Latin excipient-, excipiens, present participle of excipere to take out, take up — more at except
First Known Use
circa 1753, in the meaning defined above
Medical Definition
excipient
noun
ex·cip·i·ent ik-ˈsip-ē-ənt
: a usually inert substance (as gum arabic, syrup, lanolin, or starch) that forms a vehicle (as for a drug or antigen)
especially : one that in the presence of sufficient liquid gives a medicated mixture the adhesive quality needed for the preparation of pills or tablets