Packaging and storage— Preserve in tight containers,and avoid exposure to excessive heat.

Rosin,rosin oil,and copaiba— Place 1g,powdered or crushed if necessary,in a small mortar,and add 10mLof petroleum benzin.Triturate well for 1to 2minutes,filter into a test tube,and to the filtrate so obtained add 10mLof freshly prepared cupric acetate solution (1in 200).Shake,and allow the phases to separate:the petroleum benzin layer does not show a green color.

Acid value á401ñ— Dissolve about 1g,accurately weighed,in 50mLof neutralized alcohol,add phenolphthalein TS,and titrate with 0.5Nalcoholic potassium hydroxide VS:the acid value is between 112and 168.

Saponification value á401ñ— Add sufficient 0.5Nalcoholic potassium hydroxide VSto the neutralized liquid obtained in the test for Acid valueto make the total volume of the alkali solution added 20.0mL,heat the liquid on a steam bath for 30minutes under a reflux condenser,and cool.Add about 200mLof water,or more if necessary,and titrate the excess potassium hydroxide with 0.5Nhydrochloric acid VS.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).The total volume of 0.5Nalcoholic potassium hydroxide consumed,including that required to neutralize the free acid in the determination of Acid value,is equivalent to a saponification value of between 154and 220.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 1952

Phone Number:1-301-816-8262