Vibrational Fingerprint of Erlotinib: FTIR, RS, and DFT Studies

Abstract

In this study, we provide the first Fourier-transform infrared absorption spectroscopy (FTIR) and Raman spectroscopy (RS) analysis of a vibrational fingerprint of erlotinib, a drug which is applied in non-small cell lung cancer therapy, in solid state and solution in different pH conditions. Additionally, the performed DFT theoretical calculations in vacuum and PCM models support the interpretation of vibrational spectra and give insight into an optimized spatial configuration of the investigated drug. e present considerations show vibrational structure of erlotinib and details of its molecular geometry. Furthermore, we discuss the pH condition where the protonated -NH + and C�N + forms occur and indicate the spectral changes characteristic for the erlotinib protonation. It is of great of importance to better understand biological activity of the drug and to develop new tyrosine kinase inhibitors.

Nanoscale image of the drug/metal mono-layer interaction: Tapping AFM-IR investigations

“…This vibration also contributes to the bands at 1,578, 1,416, and 1,361 cm −1 . The observed AFM-IR spectral pattern for non-adsorbed erlotinib corresponds to the previously published results obtained by conventional Fourier transform IR spectroscopy in ATR mode [48]. However, some changes, especially in the relative intensities of the particular bands, are noted, especially for the bands at ~ 1,632 and ~ 1,445 cm −1 .…”

“…Figure 3(a) presents the AFM-IR spectrum of erlotinib alone, and in Table 1, all wavenumbers and assignments of the bands are listed. The band assignment analysis was performed based on previously published studies of the erlotinib structure coupled with density functional theory (DFT) calculations [48]. Additionally, the corresponding data for the main chemical groups present in the molecules such as aniline [49], pyrimidine [50,51], and phenylacetylene [52] were taken into consideration.…”

“…It is commonly known that how a sample is prepared for measurements may influence the acquired spectral information. Parameters such as the physical state of the sample [53], solvent (solvent effect) [54], solution pH [48], and polarization effect of crystal samples [55] determine the relative intensity of the particular bands in the vibrational spectrum. Thus, the same sample preparation was applied in the AFM-IR experiments for the non-adsorbed and adsorbed drug (please see the Sample preparation section).…”

“…The suggested assignments together with the wavenumbers (ν) and full width at half maximum (FWHM) for the significant AFM-IR bands of erlotinib alone and adsorbed on the AgNPs and AuNPs mono-layers[44,[48][49][50][51][52] …”

Investigations into the electronic properties of lorlatinib, an anti‐cancerous drug using DFT, wavefunction analysis and MD simulations

“…[ 14 ] The structural investigations, density functional theory (DFT) studies on selpercatinib and IR spectroscopy with DFT studies of erlotinib were reported. [ 15,16 ] Due to the anti‐cancerous activity of lorlatinib (LTB), the reactivity analysis together with AIM and MD simulations are reported.…”