Physico-chemical properties of two anhydrous azathioprine forms and their interaction with typical pharmaceutical excipients: highlighting new findings in drug formulation development

Bărbatu, Adrian; Lungan, Maria‐Andreea; Toulbe, N'ghaya; Smaranda, Ion; Daescu, Monica; Baibarac, M.; Manta, Corina Mihaela

doi:10.1080/03639045.2022.2032131

Cited by 2 publications

(1 citation statement)

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“…Regardless of the ST concentration in the AZA/ST mixture, exposure of the ST-interacted AZA to UV light highlighted the emergence of a band with a maximum around 346–350 nm. Recently, such a band was also reported in the case of the interaction of AZA with H 2 O 2 [ 22 ]. Other changes noted in the UV-VIS spectra of the ST-interacted AZA with an increase in the time of UV exposure were: (i) a downshift of the band from 276 nm (AZA unreacted with ST) to 274 nm ( Figure 1 a), 270 nm ( Figure 1 b) and 268 nm ( Figure 1 c); (ii) an upshift of the band from 346 nm ( Figure 1 a) to 348 nm ( Figure 1 b) and 350 nm ( Figure 1 c); and (iii) the absorbance ratio of the bands in the 245–315 nm and 315–405 nm spectral ranges (A 245-315 /A 315-405 ) became equal to 3.2 ( Figure 1 a), 2.95 ( Figure 1 b) and 4.22 ( Figure 1 c) after 6 h of UV irradiation.…”

Section: Resultsmentioning

confidence: 86%

Photodegradation of Azathioprine in the Presence of Sodium Thiosulfate

Toulbe

Smaranda

Negrilă

et al. 2022

IJMS

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The effect of sodium thiosulfate (ST) on the photodegradation of azathioprine (AZA) was analyzed by UV-VIS spectroscopy, photoluminescence (PL), FTIR spectroscopy, Raman scattering, X-ray photoelectron (XPS) spectroscopy, thermogravimetry (TG) and mass spectrometry (MS). The PL studies highlighted that as the ST concentration increased from 25 wt.% to 75 wt.% in the AZA:ST mixture, the emission band of AZA gradual downshifted to 553, 542 and 530 nm. The photodegradation process of AZA:ST induced: (i) the emergence of a new band in the 320–400 nm range in the UV-VIS spectra of AZA and (ii) a change in the intensity ratio of the photoluminescence excitation (PLE) bands in the 280–335 and 335–430 nm spectral ranges. These changes suggest the emergence of new compounds during the photo-oxidation reaction of AZA with ST. The invoked photodegradation compounds were confirmed by studies of the Raman scattering, the FTIR spectroscopy and XPS spectroscopy through: (i) the downshift of the IR band of AZA from 1336 cm−1 to 1331 cm−1, attributed to N-C-N deformation in the purine ring; (ii) the change in the intensity ratio of the Raman lines peaking at 1305 cm−1 and 1330 cm−1 from 3.45 to 4.57, as the weight of ST in the AZA:ST mixture mass increased; and (iii) the emergence of a new band in the XPS O1s spectrum peaking at 531 eV, which was associated with the C=O bond. Through correlated studies of TG-MS, the main key fragments of ST-reacted AZA are reported.

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Section: Resultsmentioning

confidence: 86%