FORSYRUP PACKAGED IN SINGLE-UNIT CONTAINERS: meets the requirements.

Mobile phase,Standard preparation,andChromatographic system— Proceed as directed in the Assayunder Lincomycin Hydrochloride.

Assay preparation— Transfer an accurately measured volume of Syrup,freshly mixed and free of air bubbles,equivalent to about 100mg of lincomycin,to a suitable container.Add 0.5mLof sodium carbonate solution (3in 10),and swirl for 30seconds,noting that a precipitate forms.Add 1.0mLof 0.2Nsodium hydroxide,swirl for 30seconds,add 10.0mLof chloroform,and shake by mechanical means for 10minutes.Centrifuge,and remove the upper aqueous layer by suction.Transfer 1.0mLof the clear chloroform layer to a suitable container,and evaporate under a stream of nitrogen to dryness.Add 10.0mLof Mobile phaseto the residue,and dissolve by swirling,sonicating if necessary.

Procedure— Proceed as directed in the Assayunder Lincomycin Hydrochloride,recording the chromatogram over a period seven times the retention time of lincomycin.Calculate the quantity,in mg,of lincomycin (C18H34N2O6S)in each mLof the Syrup taken by the formula: in which Vis the volume,in mL,of Syrup taken;and the other terms are as defined therein.