3.2. Specificity
USP defines specificity as the ability to assess unequivocally
the analyte in the presence of components that may be
expected to be present, such as impurities, degradation products,
and matrix components. The specificity of the HPLC
method was examined by peak identification; no interferences
appeared at the retention time of tetracycline hydrochloride
and 4-epianhydotetracycline hydrochloride in the chromatogram
from sample solution of capsule that contains 0.1 mg/
mL tetracycline hydrochloride (Fig. 2).