Polyester-4 is a copolymer formed by the condensation of Adipic Acid (q.v.) and Pentaerythritol (q.v.) endcapped with Caproic Acid (q.v.), heptanoic acid, Caprylic Acid (q.v.) and Capric Acid (q.v.). See Reported Ingredient Functions-The Cosmetic Drug Distinction, in Regulatory and Ingredient Use Information, Volume I, Part A.