Polymorphism control of an active pharmaceutical ingredient beneath calixarene-based Langmuir monolayers

Tulli, Ludovico G.; Moridi, Negar; Wang, Wenjie; Helttunen, Kaisa; Neuburger, Markus; Vaknin, David; Meier, Wolfgang; Shahgaldian, Patrick

doi:10.1039/c4cc00928b

Cited by 19 publications

(19 citation statements)

References 16 publications

(23 reference statements)

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“…In addition, the isotherm reveals the presence of a phase transition at 39 mN m −1 , suggesting that a molecular rearrangement of the film occurs, consistent with previously reported results. 27 In the presence of 10 −5 M aqueous CoCl 2 , NiCl 2 , and MnCl 2 subphases, the collapse pressure (55, 51, and 51 mN m −1 , respectively) and A 0 (113, 126, and 125 Å 2 molecule −1 , respectively) values are fairly close to that measured on pure water (π c = 51 mN m −1 , A 0 = 122 Å 2 molecule −1 ). The rigidity of Langmuir monolayers is typically defined by its compressibility modulus:…”

Section: ■ Results and Discussionsupporting

confidence: 59%

“…In addition, the π c increases from 51 up to 62 mN m −1 , a considerably high value for a monomolecular film formed by a calixarene-based amphiphile. Furthermore, the characteristic phase transition observed on water is absent for Cu 2+ solution at 10 −5 M. These observations indicate that Cu 2+ , Co 2+ , Ni 2+ , and Mn 2+ ions interact with the monolayer even at a relatively low concentration of 10 −5 M. In a previous work, 27 we showed that, in the solid state, 1 adopts a pinched cone conformation whereby two distal phenyl rings are splayed apart and the other two are closer to each other. The amphiphiles are self-assembled in a bilayered fashion where the carboxylic groups of adjacent macrocycles are arranged side-by-side.…”

Section: ■ Results and Discussionmentioning

confidence: 81%

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Interfacial Binding of Divalent Cations to Calixarene-Based Langmuir Monolayers

et al. 2015

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The interactions of Langmuir monolayers produced through the self-assembly of an amphiphilic p-carboxycalix[4]arene (1) with a series of divalent, fourth-period transition metals, at the air-water interface, were investigated. Changes in the interfacial behavior of 1 in response to the presence of CuCl2, CoCl2, MnCl2, and NiCl2 were studied by means of Langmuir compression isotherms and Brewster angle microscopy (BAM). The measurements revealed that the self-assembly properties of 1 are significantly affected by Cu(2+) ions. The interactions of 1-based monolayers with Co(2+) and Cu(2+) ions were further investigated by means of synchrotron radiation-based X-ray reflectivity (XRR), X-ray near-total-reflection fluorescence (XNTRF), and grazing incidence X-ray diffraction (GIXD). XNTRF and XRR analyses revealed that the monolayer of 1 binds more strongly to Cu(2+) than Co(2+) ions. In the presence of relatively high concentrations of Cu(2+) ions in the subphase (1.4 × 10(-3) M), XNTRF exhibited anomalous depth profile behavior and GIXD measurements showed considerably strong diffuse scattering. Both measurements suggest the formation of Cu(2+) clusters contiguous to the monolayer of 1.

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Section: ■ Results and Discussionsupporting

confidence: 59%

Section: ■ Results and Discussionmentioning

confidence: 81%

Interfacial Binding of Divalent Cations to Calixarene-Based Langmuir Monolayers

et al. 2015

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“…Cyclodextrins have been used to form inclusion complexes with a group of polymers, given that, by being appropriately removed, the host is forced to coalesce into a pure polymeric solid, favoring the polymorph whose structure is the most extended [65]. In the same way, using monolayers of amphiphilic calixarenes favors the formation of specific polymorphs of gabapentin [66]. An interesting application is the design of an organic semiconductor, consisting of a polymorph and a nanoprinted polyimide layer [67].…”

Section: Nucleation and Polymorphismmentioning

confidence: 99%

Crystal Growth in Gels from the Mechanisms of Crystal Growth to Control of Polymorphism: New Trends on Theoretical and Experimental Aspects

et al. 2019

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A gel can be considered to be a two-phase (liquid and solid) system, which lacks flow once it reaches a stationary state. The solid phase is usually a tridimensional polymeric mesh, while the liquid phase is usually found in three forms: contained in great cavities, retained in the capillary pores between micelles, or adsorbed on the surface of a micelle. The influence of the use of gels in crystal growth is diverse and depends on the type of gel being used. A decrease in solubility of any solute in the liquid may occur if the solvent interacts extensively with the polymeric section, hence, the nucleation in gels in these cases apparently occurs at relatively low supersaturations. However, if the pore size is small enough, there is a possibility that a higher supersaturation is needed, due to the compartmentalization of solvents. Finally, this may also represent an effect in the diffusion of substances. This review is divided into three main parts; the first evaluates the theory and practice used for the obtainment of polymorphs. The second part describes the use of gels into crystallogenesis of different substances. The last part is related to the particularities of protein crystal polymorphism, as well as modern trends in gel growth for high-resolution X-ray crystallography.

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“…2 One should point out the use of calixarenes in the biological field 3,4 and in design of pharmaceutic agents. [5][6][7] Calixarenes form metal nanoparticles, [8][9][10] e.g. AuNPs 8,9 and AgNPs, 10 as well as organic NPs, 11 and serve for construction of sensors; [12][13][14] they also may be used as extractants of f-elements.…”

Section: Introductionmentioning

confidence: 99%