Packaging and storage— Preserve in well-closed containers.

Melting range,Class IIá741ñ: between 80and 86.

Acid value— Weigh accurately 3g into a 250-mLflask attached to a reflux condenser,add 50mLof 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 about 1mLof phenolphthalein TS,and immediately titrate with 0.5Nalcoholic potassium hydroxide VSto a faint,reddish yellow color.[NOTE—Do not allow 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 1g of Carnauba Wax.The acid value so obtained is between 2and 7.

Saponification value á401ñ— To the solution from the test for Acid valueadd 15.0mLof 0.5Nalcoholic potassium hydroxide VS,reflux for 3hours,and titrate the excess alkali with 0.5Nhydrochloric acid VSto a yellow-amber color.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).The saponification value is the summation of the ester value so obtained and the Acid value,and it is between 78and 95.

Residue on ignition á281ñ— Heat 2g in an open porcelain or platinum dish over a flame:it volatilizes without emitting an acrid odor.Ignite:the weight of the residue does not exceed 5mg.Not more than 0.25%is found.

Heavy metals,Method IIá231ñ: 20µg per g.

Organic volatile impurities,Method IVá467ñ: meets the requirements.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 3106

Phone Number:1-301-816-8262