Solvent-polymer guest exchange in a carbamazepine inclusion complex: structure, kinetics and implication for guest selection

Abstract

Solvent–polymer guest exchange in a carbamazepine inclusion complex in a stirred solution was studied and a mechanism was proposed.

Intermolecular Interactions in Functional Crystalline Materials: From Data to Knowledge

“…Note, that these results coincide with those obtained for carbamazepin-containing solids using the XPac method [103].One of the carbamazepin pseudo-isostructural groups is represented by metastable polymorph II and its solvates and hydrates situated inside the channels formed by the hydrophobic aromatic surfaces of this molecule, which were found to act as stabilizers of this solid [104]. These solvent molecules within the channels can even be replaced with hydrophobic polymer guest molecules [105]. Comparison of an orthorhombic polymorph of trimeric perfluoro-ortho-phenylen mercury with its' three monoclinic polymorphs gives up to six similarly packed molecules.…”

The guest polymer effect on the dissolution of drug–polymer crystalline inclusion complexes

“…[29][30][31] In our previous study, we showed that the linear polymer, poly(tetrahydrofuran) (PTHF), could also occupy these channels as guest and form a crystalline inclusion complex. 22 The CBZ framework structures of form II and drug-polymer inclusion complex crystals are the same with each other, as evidenced by their X-ray diffraction patterns. Unlike the other drugs in our previous studies on drug-polymer inclusion complexes, the channel-type structure of CBZ form II is apparently stable even without guest occupation, thus providing the rare opportunity to directly study the guest effect.…”

“…1) were similar to each other and all consistent with that of the form II crystal in the literature. 27 As in other drug-polymer inclusion complex and channel-type solvate crystals, [12][13][14][15][16][17][18][19][20][21][22][23] the guest molecules were in the disordered state and did not contribute to diffraction peaks in diffractograms. The two inclusion complexes were crystallized in the presence of excess polymers, which were removed by rinsing the samples with suitable solvents (water for the PEG and CCl 4 for the PCL systems, respectively).…”

“…Recently, crystalline inclusion complexes (IC) between API and linear polymers have been proposed as a relatively un-explored solid form of drugs, where the crystalline structure of the drug molecules possesses continuous and void channels, and the linear polymer chains reside in such channels as guests. 11 Though the drug-polymer inclusion complex may not be universally applicable, so far, several drugs have been proven to form such interesting structure, including phenobarbital, 12,13 resorcinol, 14 mavacoxib, 15 griseofulvin, 16,17 diunisal, [18][19][20] nevirapine, 21 carbamazepine, 22 and dapsone. 23 More importantly, outside of the pharmaceutical eld, there are many more examples of crystalline inclusion complexes between polymers and small molecules, [24][25][26] suggesting the generality of such structures beyond the abovementioned cases.…”

Critical Size of Secondary Nuclei Determined via Nucleation Theorem Reveals Selective Nucleation in Three-Component Co-Crystals

“…The work is expected to deepen our understanding of the nucleation of multi-component co-crystals.Entropy 2019, 21, 1032 2 of 12 compound (IC) during its crystal growth process [17]. The PEO/urea ICs consist of guest PEO chains residing in the cavities formed by the host urea molecules [18][19][20][21][22][23][24][25][26]. By replacing a small amount of urea with N,N -dimethyl urea with the PEO concentration unchanged, we could change the rate of secondary nucleation and determine the critical size of the secondary nuclei of the PEO/urea IC β crystal.…”