Structure and properties of ibuprofen–hydroxypropyl methylcellulose nanocomposite gel

Rapid amorphization of molecular crystals by absorption of solvent molecules in the presence of hydrophilic matrices

“…As shown in Fig. 5, the drug particles, as stained by OsO 4 , are well-dispersed spherical particles in the size 60 ± 31 nm, which are very close to what we have observed in our previous study on the formation of amorphous nanoparticles of IB obtained via a sol-gel route [12]. Note that OsO 4 vapors preferentially adsorb to CHCH bonds, which is imparted to IB but not to HPMC.…”

“…These FT-IR shifts suggest the recombination of hydrogen bonds of intermolecular IB to the interaction between IB and HPMC. In our previous work, the interaction was also represented as blue shifts of FT-IR peaks [12].…”

“…We recently demonstrated rapid amorphization and nanomization of ibuprophen (IB) with the presence of hydroxypropyl methylcellulose (HPMC) to give nanocomposites by mixing clear solution of the individual species and quickly drying [12]. The method was easy and rapid but was restricted to a narrow composition range.…”

Stochiometrically governed molecular interactions in drug: Poloxamer solid dispersions

“…Recently, Rawlinson et al (2007) explored molecular associations in ibuprofen:polyvinylpyrrolidone dispersions and demonstrated the importance of hydrogen bonding between the hydroxyl moiety of the drug and carboxylic groups in the carrier, and the role of hydrophobic interactions to improve dissolution rates of the drug. These findings were subsequently confirmed by Yu et al (2009), and by Nakayama et al (2009) who suggested that hydrogen bonds within ibuprofen crystals converted to ones between ibuprofen and hydroxypropylcellulose in a nanocomposite gel.…”

Structural Characterization of Amorphous Solid Dispersions

“…Local distribution of nuclear spin density Spatial mapping of the associated component (API, polymer or dissolution medium) using T (Bikiaris et al 2005;De Zordi et al 2012;Karavas et al 2007a, b;Ma et al 2013;Nakayama et al 2009) Ultimate spatial resolution for analyzing compositional heterogeneities, density variations, grain boundaries, etc. Reasonable contrast provided by hetero-elemental API for the measurement of the dimension of amorphous drug nano-clusters dispersed in the polymer matrix TEM/EDS for drug-polymer miscibility, i.e., molecularly mixed systems appear as a continuous matrix without elemental localization (lack of local elemental spikes) Spatial distinction of nanoscopic physical structure among amorphous, crystalline, and other mesophases in heterogeneous polymeric dispersion using selective negative staining of unsaturated API by heavy metal oxides (e.g., (Lauer et al 2011Meeus et al 2013;Qi et al 2013a, b) (Antal et al 2013;Bölcskei et al 2011;Chieng et al 2013a, b;Gottnek et al 2013;Szabó et al 2011;Szente et al 2009;Zelkóa et al 2006) Very Study of miscibility in product with low drug content (0.5-1 %w/w) Estimation of domain size and identification of molecular cluster to dispersion possible Selective Not applicable for high drugloading system as API molecular proximity below FRET distance Fluorescent properties required and FRET should occur Neutron scattering (Bordallo et al 2012;Lerbret et al 2012;Magazù et al 2008;Magazù et al 2010;Qi et al 2013a, b) Molecular dynamics and structural relaxation of multicomponent amorphous systems Small-angle neutron scattering for polymer-surfactant interaction during dissolution of ternary ASD Sample preparation tedious Requires isotope labeling or enrichment ASD amorphou...…”