TY - JOUR
T1 - Interaction of Native Cyclodextrins and Their Hydroxypropylated Derivatives with Carbamazepine in Aqueous Solution. Evaluation of Inclusion Complexes and Aggregates Formation
AU - Couto, André Rodrigues Sá
AU - Ryzhakov, Alexey
AU - Larsen, Kim Lambertsen
AU - Loftsson, Thorsteinn
PY - 2019/1/16
Y1 - 2019/1/16
N2 - A detailed comprehensive study on how the formation of soluble and insoluble carbamazepine/cyclodextrins (CBZ/CD) complexes (with consequent changes in the solid-phase composition) depends on the CD structure is not yet available. Moreover, the study of possible influence of this drug on the tendency of CDs and their complexes to self-aggregate is still lacking. Phase-solubility studies demonstrated that CDs and CBZ form a range of soluble (AL-type: αCD, βCD, and hydroxypropylated CDs) and insoluble (BS-type: δCD) complexes depending on CD used. HPβCD proved to be the best CD solubilizer for CBZ forming the most stable complex with highest apparent solubility, whereas δCD was shown to be the best native CD. For the native CDs, CBZ solubilization increases with increasing CD cavity diameter (αCD â‰βCD < δCD). Solid phases collected from phase-solubility studies were characterized by Fourier-transformed infrared spectroscopy, differential scanning calorimetry, and X-ray powder diffraction to elucidate their composition and crystalline structure. They provided similar conclusions being overall supportive of phase-solubility, osmolality, and permeation studies results. Solid CBZ was the only detected component for AL-type profiles over the CD concentration range studied, whereas precipitation of poorly soluble CBZ/δCD complexes (BS-type) was observed (i.e., at and beyond plateau region). Osmometry and permeation studies were applied to evaluate the effect of CBZ on the aggregate formation and also to elucidate their influence on CD complex solubility and permeation profile. Permeation method was shown to be the most effective method to detect and evaluate aggregate formation in aqueous δCD and HPβCD solutions containing CBZ. CBZ did not affect the HPβCD tendency to self-aggregate but CBZ did modify the aggregation behavior of δCD decreasing the apparent critical aggregation concentration value from 4.2% (w/v) (in pure aqueous δCD solution) to 2.5% (w/v) (when CBZ was present).
AB - A detailed comprehensive study on how the formation of soluble and insoluble carbamazepine/cyclodextrins (CBZ/CD) complexes (with consequent changes in the solid-phase composition) depends on the CD structure is not yet available. Moreover, the study of possible influence of this drug on the tendency of CDs and their complexes to self-aggregate is still lacking. Phase-solubility studies demonstrated that CDs and CBZ form a range of soluble (AL-type: αCD, βCD, and hydroxypropylated CDs) and insoluble (BS-type: δCD) complexes depending on CD used. HPβCD proved to be the best CD solubilizer for CBZ forming the most stable complex with highest apparent solubility, whereas δCD was shown to be the best native CD. For the native CDs, CBZ solubilization increases with increasing CD cavity diameter (αCD â‰βCD < δCD). Solid phases collected from phase-solubility studies were characterized by Fourier-transformed infrared spectroscopy, differential scanning calorimetry, and X-ray powder diffraction to elucidate their composition and crystalline structure. They provided similar conclusions being overall supportive of phase-solubility, osmolality, and permeation studies results. Solid CBZ was the only detected component for AL-type profiles over the CD concentration range studied, whereas precipitation of poorly soluble CBZ/δCD complexes (BS-type) was observed (i.e., at and beyond plateau region). Osmometry and permeation studies were applied to evaluate the effect of CBZ on the aggregate formation and also to elucidate their influence on CD complex solubility and permeation profile. Permeation method was shown to be the most effective method to detect and evaluate aggregate formation in aqueous δCD and HPβCD solutions containing CBZ. CBZ did not affect the HPβCD tendency to self-aggregate but CBZ did modify the aggregation behavior of δCD decreasing the apparent critical aggregation concentration value from 4.2% (w/v) (in pure aqueous δCD solution) to 2.5% (w/v) (when CBZ was present).
UR - http://www.scopus.com/inward/record.url?scp=85060179079&partnerID=8YFLogxK
U2 - 10.1021/acsomega.8b02045
DO - 10.1021/acsomega.8b02045
M3 - Journal article
AN - SCOPUS:85060179079
SN - 2470-1343
VL - 4
SP - 1460
EP - 1469
JO - ACS Omega
JF - ACS Omega
IS - 1
ER -