Identification
To an accurately measured volume of Oral Suspension,equivalent to about 50mg of methacycline,add 50mLof methanol,shake,and allow the mixture to settle.Using the clear supernatant as the
Test Solution,proceed as directed for
Method IIunder
IdentificationTetracyclines á193ñ.
Assay
Mobile phase
,System suitability preparation,and Chromatographic systemProceed as directed in the Assayunder Methacycline Hydrochloride.
Standard preparation
Transfer about 28mg of
USP Methacycline Hydrochloride RS,accurately weighed,to a 50-mLvolumetric flask,add 10mLof water,dilute with
Mobile phaseto volume,and mix.
Assay preparation
Transfer an accurately measured quantity of Oral Suspension,freshly mixed and free from air bubbles,equivalent to about 50mg of methacycline (C22H22N2O8),to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,mix,and filter.
Procedure
Proceed as directed in the
Assayunder
Methacycline Hydrochloride.Calculate the quantity,in mg,of methacycline (C
22H
22N
2O
8)in each mLof the Oral Suspension taken by the formula:
100(CE/1000V)(rU/rS),
in which
Vis the volume,in mL,of Oral Suspension taken to prepare the
Assay preparation;and the other terms are as defined therein.