Yellow Wax
Yellow Wax is the purified wax from the honeycomb of the bee [Apis mellifera L. (Fam. Apidae)]. The crude beeswax used to prepare Yellow Wax conforms to the Saponification Cloud Test.
•  Saponification Cloud Test
Sample:  3.00 g
Alcoholic potassium hydroxide:  Dissolve 40 g of potassium hydroxide in about 900 mL of aldehyde-free alcohol maintained at a temperature not exceeding 15, and then when solution is complete, warm to room temperature, and add aldehyde-free alcohol to make 1000 mL.
Analysis:  Place the Sample in a 100-mL round-bottom boiling flask fitted with a ground-glass joint. Add 30 mL of Alcoholic potassium hydroxide. Reflux the mixture gently for 2 h. At the end of this period, open the flask, insert a thermometer into the solution, and place the flask in a container of water at a temperature of 80. Rotate the flask in the bath while both the bath and the solution cool.
Acceptance criteria:  The solution shows no cloudiness or globule formation before the temperature reaches 65.
•  Fats or Fatty Acids, Japan Wax, Rosin, and Soap
Sample:  1 g
Analysis 1:  Boil the Sample for 30 min with 35 mL of 3.5 N sodium hydroxide contained in a 100-mL beaker, maintaining the volume of solution by the occasional addition of water, and allow the mixture to cool at room temperature for about 2 h.
Acceptance criteria 1:  The wax separates, leaving the liquid clear, turbid, or translucent, but not opaque.
Analysis 2:  Filter the cool mixture obtained in Analysis 1, and acidify the clear filtrate with hydrochloric acid.
Acceptance criteria 2:  The liquid remains clear or shows NMT a slight amount of turbidity or precipitate.
•  Fats and Fixed Oils, Acid Value (Free Fatty Acids) 401
Sample:  3 g
Analysis:  Warm the Sample in a 200-mL flask with 25 mL of neutralized dehydrated alcohol until melted, then shake the mixture. Add 1 mL of phenolphthalein TS, and titrate the warm liquid with 0.5 N alcoholic potassium hydroxide VS to produce a permanent, faint pink color. Calculate the Acid Value as directed in the chapter.
Acceptance criteria:  17–24
•  Fats and Fixed Oils, Ester Value 401
Sample solution:  The solution resulting from the determination of Acid Value
Analysis:  To the Sample solution add 25.0 mL of 0.5 N alcoholic potassium hydroxide VS and 50 mL of aldehyde-free alcohol, and reflux the mixture for 4 h. Titrate the excess alkali with 0.5 N hydrochloric acid VS. Perform a blank determination (see Titrimetry 541, Residual Titrations). Calculate the Ester Value as directed in the chapter.
Acceptance criteria:  72–79
•  Packaging and Storage: Preserve in well-closed containers.
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Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
(EXC2010) Monographs - Excipients
USP35–NF30 Page 2016