λ (nm) Declared content (mg) Founda (mg) Recovery% RSD% AM           Brand 1             238 5 4.34 ± 0.06 86.9 1.41   268 5 5.54 ± 0.02 110.8 0.38   269 5 5.52 ± 0.02 110.4 0.37   270 5 5.51 ± 0.02 110.3 0.37 Brand 2             238 5 4.28 ± 0.11 85.6 2.68   268 5 5.45 ± 0.10 109.0 1.75   269 5 5.45 ± 0.08 109.1 1.41   270 5 5.47 ± 0.06 109.4 1.08 AT           Brand 1             235 20 20.88 ± 0.03 104.4 0.15   256 20 19.52 ± 0.03 97.6 0.16   309 20 19.93 ± 0.01 99.7 0.04   310 20 19.79 ± 0.01 98.9 0.07 Brand 2             235 20 20.88 ± 0.03 104.4 0.13   256 20 19.51 ± 0.02 97.5 0.12   309 20 19.93 ± 0.01 99.7 0.04   310 20 19.78 ± 0.01 98.9 0.06 aMean of five determinations.

Table 7: Results of application of CWT zero-crossing method on the spectra of the pharmaceutical preparations.