METHODS: Polymeric carriers with different hydrophobic to hydrophilic ratios were used to prepare several electrospun solid dispersion formulations. Physicochemical properties and surface morphology of the samples were assessed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), polarized light microscopy, Differential Scanning Calorimetry (DSC), X-ray Powder Diffraction (XRPD) and Scanning Electron Microscopy (SEM). Dissolution study was conducted in a non-sink condition to assess the drug release.
RESULTS: Incorporation of a higher amount of hydrophilic component showed an improvement in formulating a fully amorphous system based on XRPD, yet the dissolution rate increment showed no significant difference from the lower. Hence, the degree of crystallinity is proven not to be the crucial factor contributing to dissolution rate improvement. The presence of a concomitant hydrophobic component, however, showed ability in resisting precipitation and sustaining supersaturation.
CONCLUSION: Hydrophobicity in a binary carrier system plays an important role in achieving and maintaining the supersaturated state particularly for an amorphous solid dispersion. Graphical Abstract.
RESULTS: Analytes were gradiently separated on a C18 column and detected with a Sciex API 4000 MS/MS with an ESI source operated in the positive ion mode with deuterated PQ as internal standard. The response was linear in the range 3.9-2508nM with a runtime of 7.0min per sample. The method was applied to clinical samples from healthy volunteers.
CONCLUSION: This LC-MS/MS method for the simultaneous quantitation of PQ and two of its metabolites in plasma may prove helpful for assessment of metabolite safety issues in vivo.