Carnauba Wax
DEFINITION
Carnauba Wax is obtained from the leaves of Copernicia cerifera Mart. (Fam. Palmae).
IMPURITIES
•  Residue on Ignition 281
Sample:  2 g
Analysis:  Heat the Sample in an open porcelain or platinum dish over a flame: it volatilizes without emitting an acrid odor. Ignite.
Acceptance criteria:  The weight of the residue is NMT 5 mg, corresponding to NMT 0.25%.
SPECIFIC TESTS
•  Acid Value
Sample:  3 g
Analysis:  Weigh the Sample into a 250-mL flask attached to a reflux condenser. Add 50 mL of a mixture of isopropyl alcohol and toluene (5:4), and boil gently until the wax is completely dissolved. Remove the flask from the condenser, add 1 mL of phenolphthalein TS, and immediately titrate with 0.5 N alcoholic potassium hydroxide VS to a faint, reddish-yellow color. [Note—Do not allow the solution to cool. Titrate at warm temperature after refluxing. ]
Calculate the acid value as the number of mg of potassium hydroxide required to neutralize the free acids in 1 g of Carnauba Wax.
Acceptance criteria:  2–7
•  Fats and Fixed Oils, Saponification Value 401
Sample:  Use the solution from the test for Acid Value.
Analysis:  To the Sample add 15.0 mL of 0.5 N alcoholic potassium hydroxide VS, reflux for 3 h, and titrate the excess alkali with 0.5 N hydrochloric acid VS to a yellow-amber color. Perform a blank determination (see Titrimetry 541, Residual Titrations).
Calculate the ester value. The saponification value is the sum of the ester value and the acid value.
Acceptance criteria:  78–95
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
1-301-816-8335
(EXC2010) Monographs - Excipients
USP35–NF30 Page 2015