title: Analysis of feed blends containing microencapsulated 2-ethyl-1-hexanol: verification of homogeneity and stability.
abstract: 2-Ethyl-1-hexanol (2-EH) was nominated for carcinogenicity testing by the National Toxicology Program because it is a high-volume chemical and a major metabolite of di(2-ethylhexyl)phthalate, a known hepatocarcinogen and a known contaminant in blood storage bags. In addition to uses as an intermediate in the manufacture of plasticizers. 2-EH is also used as a solvent, a lubricant and as a finishing compound for paper and textiles. The preferred route of administration for the carcinogenicity studies was oral via the diet. However, feed blends containing neat 2-EH were not sufficiently stable for feed studies. Dosed feed blends prepared with neat 2-EH retained only 86% of the theoretical concentration after blending, and 46% of theoretical after storage for 2 days in a rat cage environment. Feed blends containing microencapsulated 2-EH were sufficiently stable for toxicity studies: no losses of 2-EH were observed after blending, feed blends stored for 7 days in a rat cage retained 99% of the theoretical concentration and blends stored in sealed containers at room temperature for 21 days retained 97% of the theoretical concentration. These studies demonstrate the potential for microencapsulation technology to eliminate dose formulation problems associated with volatile chemicals.
authors.affiliation: Midwest Research Institute, Kansas City, MO 64110, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Arneson
authors.forename: G O
authors.initials: GO
authors.lastname: Kuhn
authors.forename: C W
authors.initials: CW
authors.lastname: Jameson
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002273:Carcinogens / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D002849:Chromatography, Gas; D004339:Drug Compounding; D004355:Drug Stability; D005503:Food Additives / Q000032:analysis; D000441:Hexanols / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D010968:Plasticizers / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D051381:Rats; D012015:Reference Standards
chemical_list: D002273:Carcinogens; D005503:Food Additives; D000441:Hexanols; D010968:Plasticizers; C034017:2-ethylhexanol