Alastair J Florence

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The use of high-energy X-ray total scattering coupled with pair distribution function analysis produces unique structural fingerprints from amorphous and nanostructured phases of the pharmaceuticals carbamazepine and indomethacin. The advantages of such facilitybased experiments over laboratory-based ones are discussed and the technique is illustrated with(More)
Two multisample laboratory powder diffractometers have been evaluated for the purpose of pattern indexing in the context of physical form screening. Both diffractometers utilise foil transmission geometry, primary monochromated radiation, and a position-sensitive detector. Data collected from six compounds (sotalol hydrochloride, hydroflumethiazide,(More)
An automated parallel crystallisation search for physical forms of carbamazepine, covering 66 solvents and five crystallisation protocols, identified three anhydrous polymorphs (forms I-III), one hydrate and eight organic solvates, including the single-crystal structures of three previously unreported solvates (N,N-dimethylformamide (1:1); hemi-furfural;(More)
Bendroflumethiazide, or 3-benzyl-6-(trifluoromethyl)-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide, is reported to crystallize as 1:1 solvates with acetone, C(15)H(14)F(3)N(3)O(4)S(2).C(3)H(6)O, and N,N-dimethylformamide, C(15)H(14)F(3)N(3)O(4)S(2).C(3)H(7)NO. A detailed investigation of the crystal packing and intermolecular interactions(More)
This whitepaper highlights current challenges and opportunities associated with continuous synthesis, workup, and crystallization of active pharmaceutical ingredients (drug substances). We describe the technologies and requirements at each stage and emphasize the different considerations for developing continuous processes compared with batch. In addition(More)
The purpose of this study was to investigate the variability in the performance of a pulsatile capsule delivery system induced by wet granulation of an erodible HPMC tablet, used to seal the contents within an insoluble capsule body. Erodible tablets containing HPMC and lactose were prepared by direct compression (DC) and wet granulation (WG) techniques and(More)
The predictions of the crystal structure of 3-azabicyclo[3.3.1]nonane-2,4-dione submitted in the 2001 international blind test of crystal structure prediction (CSP2001) led to the conclusion that crystal structures containing an alternative hydrogen bonded dimer motif were energetically competitive with the known catemer-based structure. Here we report an(More)
Cytenamide forms a 1:1 solvate with trifluoro-acetic acid (systematic name: 5H-dibenzo[a,d]cyclo-hepta-triene-5-carboxamide trifluoro-acetic acid solvate), C(16)H(13)NO·C(2)HF(3)O(2). The compound crystallizes with one mol-ecule of cytenamide and one of trifluoro-acetic acid in the asymmetric unit; these are linked by O-H⋯O and N-H⋯O hydrogen bonds to form(More)
The crystal structures of gamma-carbamazepine (P1, Z' = 4) and chlorothiazide N,N-dimethylformamide solvate (1/2) (P2(1)/c, Z' = 2) have been determined from synchrotron and laboratory X-ray powder diffraction data, respectively, using simulated annealing. Both structures represent a significant challenge for global optimization and the successful solutions(More)
To determine the optimal measurement strategy for fingerprinting condensed phases of pharmaceutical systems using atomic pair distribution functions (PDFs) obtained from data collected using several types of x-ray diffraction instruments. PDFs of crystalline and amorphous-phase molecular systems derived from data accessible to copper-, molybdenum-, and(More)