Candelilla Wax
(kan'' de lil' la).
Candelilla Wax is the purified wax obtained from the leaves of the candelilla plant, Euphorbia antisyphilitica Zucc.
•  A. Infrared Absorption 197F
Sample:  Use a thin film of melted Candelilla Wax.
Acceptance criteria:  Meets the requirements
•  B. It meets the requirements of the test in Specific Tests for Melting Range or Temperature, Class II 741.
•  Limit of Lead 251
Sample:  3.3 g
Control:  10 µg of lead from a Diluted Standard Lead Solution (1 µg/mL of lead)
Analysis:  Weigh the Sample into a porcelain dish, heat on a hot plate until completely charred, then heat in a muffle furnace at 480 for 8 h or overnight, and cool. Cautiously add 5 mL of nitric acid, evaporate to dryness on a hot plate, then heat again in the muffle furnace for exactly 15 min, and cool. Extract the ash with two 10-mL portions of water, filtering each extract into a separator. Leach any insoluble material on the filter with 6 mL of Ammonium Citrate Solution, 2 mL of Hydroxylamine Hydrochloride Solution, and 5 mL of water, adding the filtered washings to the separator. Continue as directed in Lead 251, Procedure, beginning with “Add two drops of phenol red TS”, and use 10 mL of Diluted Standard Lead Solution for a control.
Acceptance criteria:  The color of the Sample solution does not exceed that in the control, corresponding to NMT 3 µg/g.
•  Heavy Metals, Method II 231: NMT 20 µg/g
•  Fats and Fixed Oils, Acid Value 401
Sample:  3 g
Analysis:  Weigh the Sample in a 250-mL flask, add 50 mL of a mixture of isopropyl alcohol and toluene (5:4), attach the flask to a reflux condenser, and boil gently until the wax is completely dissolved. Examine the solution: no insoluble particles are present. Remove the flask from the condenser, add 1 mL of phenolphthalein TS, and titrate immediately with 0.5 N alcoholic potassium hydroxide VS to a faint, reddish-yellow color. [Note—Do not allow the solution to cool; titrate at a warm temperature after refluxing. After the titration, reserve the solution for use in the test for Saponification Value. ]
Calculate the acid value as the number of mg of potassium hydroxide required to neutralize the free acids in 1 g of Candelilla Wax.
Acceptance criteria:  12–22
•  Fats and Fixed Oils, Saponification Value 401
Sample solution:  Use the solution from the test for Acid Value.
Analysis:  To the Sample solution add 15.0 mL of 0.5 N alcoholic potassium hydroxide VS, reflux for 3–4 h, and titrate the excess alkali with 0.5 N hydrochloric acid VS to a yellow-amber color. Perform a blank determination under the same conditions (see Titrimetry 541, Residual Titrations). The saponification value is the summation of the ester value so obtained and the acid value obtained above.
Acceptance criteria:  43–65
•  Packaging and Storage: Preserve in well-closed containers. No storage requirements specified.
•  USP Reference Standards 11
USP Candelilla Wax RS
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Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
(EXC2010) Monographs - Excipients
Reference Standards RS Technical Services
USP35–NF30 Page 1725
Pharmacopeial Forum: Volume No. 30(3) Page 966