Compatibility study of tobramycin and pharmaceutical excipients using differential scanning calorimetry, FTIR, DRX, and HPLC

ROSASCO, MARÍA A.; BONAFEDE, SILVINA L.; FAUDONE, SONIA N.; SEGALL, ADRIANA I.

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

SPRINGER

Año: 2018

1388-6150

ifferential scanning calorimetry (DSC), isothermal stress testing?Fourier transform infrared spectroscopy (IST?FTIR), isothermal stress testing?high-performance liquid chromatography, and powder X-ray diffraction (PDRX) were used as screening techniques for assessing the compatibility of tobramycin with some currently employed ophthalmic excipients. In the first phase of the study, DSC was used as a tool to detect any interaction. The absolute value of the difference between the enthalpy of the pure tobramycin melting peak and that of its melting peak in the different analyzed mixtures was chosen as a parameter of the drug?excipient interaction degree. DSC results demonstrated that benzalkonium chloride, monobasic sodium phosphate, boric acid, edetate disodium, sodium metabisulfite, thimerosal, and potassium sorbate interact with tobramycin. Taking into account these results, it could be suggested that some of the changes observed in the IST?FTIR spectra of binary blends of tobramycin