Browsing College of Science by Author "Erxleben, Andrea"
Now showing items 21-39 of 39
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Influence of excipients on cocrystal stability and formation
Aljohani, Marwah; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2020-05-26)Cocrystal formation is widely used to modify and optimize the physicochemical properties of an active pharmaceutical ingredient (API). However, the stability of cocrystals toward formulation with excipients is little ... -
Investigation of non-covalent interactions of metal complexes with DNA in cell-free systems
Erxleben, Andrea (Schweizerische Chemische Gesellschaft, 2017-03-01)Non-covalent interactions of metallo compounds with DNA range from the simple, unspecific electrostatic binding of a positively charged metal complex to the sequence-selective recognition of DNA binding sites due to shape, ... -
Investigation of the formation of drug-drug cocrystals and coamorphous systems of the antidiabetic drug gliclazide
Aljohani, Marwah; MacFhionnghaile, Pól; McArdle, Patrick; Erxleben, Andrea (Elsevier, 2019-02-23)The antidiabetic drug gliclazide (GLZ) has a slow absorption rate and a low bioavailability due to its poor solubility. GLZ is often prescribed along with an antihypertensive, as many diabetic patients have coexistent ... -
Manipulating cocrystal size and morphology using a combination of temperature cycling and additives
Civati, Francesco; Svoboda, Vaclav; Urwin, Stephanie Jane; McArdle, Patrick; Erxleben, Andrea; Croker, D.; ter Horst, Joop (American Chemical Society, 2020-11-20)A cooling crystallization of benzoic acid and isonicotinamide in ethanol yields the 1:1 cocrystal with an extreme needle-like morphology with an initial mean aspect ratio of ∼10 and a size of ∼64 μm. We demonstrate that ... -
The natural bile acid surfactant sodium taurocholate (NaTC) as a coformer in coamorphous systems: Enhanced physical stability and dissolution behavior of coamorphous drug-NaTc systems
Gniado, Katarzyna; MacFhionnghaile, Pól; McArdle, Patrick; Erxleben, Andrea (Elsevier, 2018-10-28)The amorphization of 18 different drugs on milling with one mole equivalent sodium taurocholate (NaTC) was investigated. In all cases the X-ray powder pattern showed an amorphous halo after milling at room temperature or ... -
Oxidative stress induced by Pt(IV) pro-drugs based on the cisplatin scaffold and indole carboxylic acids in axial position
Tolan, Dina; Gandin, Valentina; Morrison, Liam; El-Nahas, Ahmed; Marzano, Cristina; Montagner, Diego; Erxleben, Andrea (Nature Publishing Group, 2016-06-11)The use of Pt(IV) complexes as pro-drugs that are activated by intracellular reduction is a widely investigated approach to overcome the limitations of Pt(II) anticancer agents. A series of ten mono- and bis-carboxylated ... -
Phosphate diester cleavage, DNA interaction and cytotoxic Activity of a bimetallic bis(1,4,7-triazacyclononane) zinc complex
Montagner, Diego; Gandin, Valentina; Marzano, Cristina; Erxleben, Andrea (Wiley, 2014-06-24)The dinuclear zinc complex [Zn-2{bcmp(-H)}(mu-Cl)](ClO4)(2)center dot H2O {bcmp = 2,6-bis(1,4,7-triazacyclonon-1-ylmethyl)-4-methylphenol} has been synthesized and structurally characterized. The DNA binding affinity was ... -
A phosphate-targeted dinuclear Cu(II) complex combining major groove binding and oxidative DNA cleavage
Molphy, Zara; Montagner, Diego; Bhat, Satish S .; Slator, Creina; Long, Conor; Erxleben, Andrea; Kellett, Andrew (Oxford University Press, 2018-09-17)Free radical generation is an inevitable consequence of aerobic existence and is implicated in a wide variety of pathological conditions including cancer, cardiovascular disease, ageing and neurodegenerative disorder. Free ... -
Rapid hydrolysis of phosphate monoesters by zirconium(IV) complexes in neutral solution
Erxleben, Andrea; Coleman, Fergal (2012)Three zirconium(IV) complexes (1-3) with mono- and dinucleating tripodal ligands are reported that promote the hydrolysis of the phosphate monoesters p-nitrophenyl phosphate (NPP) and phenyl phosphate (PP) in neutral ... -
Salts, binary and ternary cocrystals of pyrimethamine: mechanosynthesis, solution crystallization and crystallization from the gas phase
O’Malley, Ciaran; Bouchet, Chloe; Manyara, Grayce; Walsh, Niamh; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2020-11-24)A series of salts and binary and ternary cocrystals of the antimalaria drug pyrimethamine (PYR) are reported. PYR has a donor–acceptor–donor (DAD) and a donor–acceptor (DA) binding site, and cocrystallization experiments ... -
Solid-state transformations of sulfathiazole polymorphs: The effects of milling and humidity
Hu, Yun; Erxleben, Andrea; Hodnett, Kieran; Li, Boyan; McArdle, Patrick; Rasmuson, Åke C.; Ryder, Alan G. (American Chemical Society, 2013-07-11)The effect of milling on the transitions of sulfathiazole polymorphs in the absence and presence of solvent and excipients was monitored by X-ray powder diffraction (XRPD), attenuated total reflectance infrared (ATR-IR), ... -
Spontaneous solid-state cocrystallization of caffeine and urea
MacFhionnghaile, Pól; Crowley, Clare M.; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2020-01-09)The cocrystallization of caffeine and urea was monitored and analyzed using infrared spectroscopy, Raman microscopy, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. The caffeine-urea ... -
Sulfamerazine: Understanding the influence of slip planes in the polymorphic phase transformation through X-ray crystallographic studies and ab initio lattice dynamics
Pallipurath, Anuradha R.; Skelton, Jonathan M.; Warren, Mark R.; Kamali, Naghmeh; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2015-08-28)Understanding the polymorphism exhibited by organic active-pharmaceutical ingredients (APIs), in particular the relationships between crystal structure and the thermodynamics of polymorph stability, is vital for the ... -
Supramolecular Structures and Tautomerism of Carboxylate Salts of Adenine and Pharmaceutically Relevant N-6-Substituted Adenine
McHugh, Charlene; Erxleben, Andrea (2011)Co-crystal and salt formation of the kinetin analogue N-6-benzyladenine with the pharmaceutically acceptable co-crystal and salt formers maleic acid, oxalic acid, glutaric acid, succinic acid, benzoic acid, and fumaric ... -
Tailoring cocrystal and salt formation and controlling the crystal habit of diflunisal
Pallipurath, Anuradha R.; Civati, Francesco; Eziashi, Magdalene; Omar, Elaf; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2016-09-26)Crystal habit modification of the drug diflunisal that normally grows into extremely thin, long needles has been achieved by breaking the stacking effect with the help of coformers. Eight new cocrystals are reported, along ... -
Unexpected effects of catalytic amounts of additives on crystallization from the gas phase: Depression of the sublimation temperature and polymorph control
Kamali, Naghmeh; Erxleben, Andrea; McArdle, Patrick (American Chemical Society, 2016-04-11)Sublimation of carbamazepine, piracetam, diflunisal, and p-minobenzoic acid is enhanced by the presence of additives. Temperature reductions and polymorph control have been observed. Sublimation of carbamazepine containing ... -
Unprecedented morphology control of gas phase cocrystal growth using multi zone heating and tailor made additives
O'Malley, Ciaran; Erxleben, Andrea; Kellehan, Seamus; McArdle, Patrick (Royal Society of Chemistry, 2020-04-15)Herein, it is shown for the first time that cocrystals can be grown by cosublimation with unprecedented morphology control using tailor made additives. Multicrystalline sea-urchin motifs and solids that look like candy-floss ... -
Use of sublimation catalysis and polycrystalline powder templates for polymorph control of gas phase crystallization
Kamali, Naghmeh; O’Malley, Ciaran; Mahon, Mary F.; Erxleben, Andrea; McArdle, Patrick (American Chemical Society, 2018-05-08)In pursuit of a solvent-free green alternative to solution-based processes, we have applied the combined use of catalytic additives and polycrystalline powder templates for polymorph control of gas phase crystallization ... -
The very different effect of water on nucleation, crystallization, and hydrate stability of zingerone and vanillate esters
Aljohani, Marwah; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2020-01-09)Vanillin and vanillate esters are widely used as flavorings in the food industry, and the vanillin derivative zingerone is one of the compounds found in the spice ginger. Neither the growth of single crystals of zingerone ...