The Specificity of the method was established by injecting a Blank, (diluent) Placebo and Sample Preparations into the chromatograph. No interference was observed. This indicates that the solvent does not interfere with drug peak and shows a good resolution.
The peak area responses of all solutions over concentration levels ranging from 40% to 160% of target concentration were measured in triplicate. A linear correlation was obtained between peak area and concentration of Erythromycin estolate for LC method. The linearity of the calibration curves was validated by the value of correlation coefficients of the regression
(r = 0.9999).The regression analysis of the calibration curves is shown in Figure 3.