Skip to main content

Advertisement

Table 1 Optimization of the chromatographic parameters for separation of mixture of FF and GLY by the proposed IPC method

From: Multiple analytical methods for determination of formoterol and glycopyrronium simultaneously in their novel combined metered dose inhaler

Parameter No. of theoretical plates (N) Mass distribution ratio (Dm) Resolution (Rs) Relative retention (α)
FF GLY FF GLY Rs PP
pH 3.0 3274 2981 1.19 2.96 6.55 2.49
4.0 1213 2630 1.15 2.82 5.0 2.45
5.0 1024 2081 1.1 2.66 4.82 2.41
6.0 887 1673 1.08 2.65 4.39 2.45
Organic modifier type Acetonitril 3274 2981 1.19 2.96 6.55 2.49
Methanol 2036 1285 0.89 1.17 5.6 1.31
Ratio of [acidified water: acetonitrile] 0.025% SDS (30:70) Un retained peak
(40:60) 3247 2981 1.19 2.96 6.55 2.49
(45:55) 2200 2410 1.27 3.05 4.92 2.39
(50:50) 2070 725 1.94 4.42 3.75 2.27
(60:40) 1834 512 2.14 4.78 4.5 2.23
Conc. of SDS % 0.015 Un ret. 1862 0 1.4 0 0
0.02 1246 2584 0.66 2.0 5.33 3.0
0.025 3274 2681 1.19 2.96 6.55 2.49
0.03 1601 1910 0.88 2.61 5.64 2.93
  1. Where: number of theoretical plates (N) = 5.45(tR/Wh/2)2
  2. Resolution (R) = 2∆ tR/W1 + W2
  3. Mass distribution ratio (Dm) = tR − tm/tm
  4. Relative retention (α) = Dm2/Dm1
  5. tR is the retention time of the substance measured from the point of injection and tM is the retention time of a non-retained marker and Wh/2 is the peak width at the half height
  6. W1 and W2 are the width of the peaks of the two components at their bases