Chem.Commun. (2009), , 773

​T. Friscic, L. R. MacGillivray, Chem. Commun., 773-775, 2009.
​Pseudoseeding involves templating a specific crystal structure architecture for a compound by seeding with crystals of a structurally-related, or homologous, system. In this study, the authors demonstrate the use of pseudoseeding to engineer a cocrystal with a 1D hydrogen bonded chain when otherwise the components would form a photoactive 0D hydrogen bonded assembly. The technique could potentially be used to dictate topologies of other co-crystals, thus significantly expanding the possibilites for co-crystal design.

CrystEngComm (2009), 11, 1396

​F. P. A. Fabbiani, B. Dittrich, A. J. Florence, T. Gelbrich, M. B. Hursthouse, W. F. Kuhs, N. Shankland, H. Sowa, CrystEngComm, 11, 1396-1406, 2009.
​The authors describe an study based on two goals; attempting to expand the search space for crystallisation of novel forms of a compound and tuning a specific process to achieve a desired physical form outcome. Using high pressure, new polymorphs of ciprofloxacin hemi Na salt pentahydrate and ciprofloxacin Na salt pentahydrate were obtained, some of which could be recovered to ambient pressure successfully. A previously unknown structure of anhydrous ciprofloxacin was also determined from powder diffraction data in a parallel study. Packing analyses of all the new forms obtained were peformed showing a high degree of similarity between the forms.

Cryst.Growth Des. (2009), 9, 951

​P. M. Bhatt, Y. Azim, T. S. Thakur, G. R. Desiraju, Cryst. Growth Des., 9, 951–957, 2009.
​A study of the co-crystal forming abilities of the anti-HIV drugs lamivudine and zidovudine has been performed. The authors investigate using designed synthons to predict co-crystallisation as well as using a non-specific screening technique. Five new co-crystals are reported here including a lamivudine:zidovudine co-crystal hydrate.

Cryst.Growth Des. (2009), 9, 1833

​Y.-H. Kiang, W. Xu, P. W. Stephens, R. G. Ball, N. Yasuda, Cryst. Growth Des., 9, 1833–1843, 2009.
​This study looks at the crystalline form behaviour of a pharmaceutical compound for which cracking of tablets was observed at high relative humidity. The compound was found to have a definite layered structure and, when exposed to moisture, the crystals absorb water into the spaces between the layers. Four hydrated forms of the compound have been identified, including a pentahydrate form, where each additional water of hydration increases the interlayer spacing by ~1.3 Å.

Cryst.Growth Des. (2009), 9, 1106

​D. R. Weyna, T. Shattock, P. Vishweshwar, M. J. Zaworotko, Cryst. Growth Des., 9, 1106–1123, 2009.
​The technique of solvent drop grinding (SDG), also known as liquid assisted grinding, wet cogrinding or mechanochemistry, is investigated using a large range of co-crystallisation experiments to determine reliability with respect to slow evaporation techniques. A set of 17 new co-crystals formed using either of the COOH···N(arom) or OH···N(arom) supramolecular heterosynthons are reported and it is shown that they can each by obtained using slow evaporation from solution or SDG. Eight co-crystals of carbamazepine that were originally crystallised by slow evaporation are also shown to be accessible using SDG. These results suggest that SDG is a reliable technique for forming co-crystals, as well as being a relatively inexpensive and green method.

Cryst.Growth Des. (2009), 9, 1082

​K. M. Anderson, M. R. Probert, C. N. Whiteley, A. M. Rowland, A. E. Goeta, J. W. Steed, Cryst. Growth Des., 9, 1082–1087, 2009.
​The authors show that molecules which crystallise with Z\' > 1 show a significantly greater tendency to form co-crystals than molecules which crystallise in their pure form with Z\' = 1 based on analysis of the Cambridge Structural Database. This is also found to be true when looking at a subset of the database containing only

Cryst.Growth Des. (2009), 9, 5108

V. Andre, D. Braga, F. Grepioni, M. T. Duarte, Cryst. Growth Des., 9, 5108–5116, 2009.
​4-Aminosalicylic acid (ASA) is an antibiotic that has been used since the 1940s in the treatment of tuberculosis. There only three published organic crystal forms of ASA - the pure form of ASA, a hydrochloride salt and a co-crystal with sulfadimidine. Reaction of ASA with 6-membered ring compounds such as dioxane, morpholine, and piperazine, yielded a solvate and three molecular salts. All forms were obtained primarily by direct mixing of the crystal partners whether liquid (such as dioxane, morpholine) or solid (ASA), without solvent being used.

Cryst.Growth Des. (2009), 9, 5283

​F. T. Martins, N. Paparidis, A. C. Doriguetto, J. Ellena, Cryst. Growth Des., 9, 5283-5292, 2009.
​Lamivudine is nucleoside reverse transcriptase inhibitor (NRTI) that is used in anti-HIV therapy. On the basis of a known lamivudine saccharinate structure reported in the literature, maleic acid was successfully chosen to synthesize a new salt form with the anti-HIV drug because of the structural similarities between the counterions. The authors also suggest that multicomponent molecular crystals of lamivudine with other salt formers can be engineered successfully using this type of method.

Cryst.Growth Des. (2009), 9, 327

​J. Galcera, E. Molins, Cryst. Growth Des., 9, 327–334, 2009.
​Lamotrigine is an anticonvulsant drug compound with a relatively low water solubility (~0.6 mM/L) and as such is potentially a good candidate for salt formation in order to improve the solid form physical properties. This publication looks at a set of four pseudo-isostructural lamotrigine salt structures containing different counterions. In this series the counterions are all dicarboxylic acids and the host framework is basically identical, but the solubility changes across the series by a factor of six.

Cryst.Growth Des. (2009), 9, 1344

​M. K. Stanton, S. Tufekcic, C. Morgan, A. Bak , Cryst. Growth Des., 9, 1344–1352, 2009.
​An analysis of 15 pharmaceutical multicomponent crystals has been undertaken involving the active pharmaceutical ingredient (API) AMG 517 and related molecules. The compound AMG 517 is a small molecule transient receptor potential vanilliod 1 (TRPV1) antagonist developed for the treatment of chronic pain. The crystal forms include 14 co-crystals and one partial salt utilising using di- and tri-acids as well as amides for co-formers. All AMG 517 co-crystals for which single crystals were obtained utilized the same hydrogen-bond donor and acceptor on the drug substance. The ability to form co-crystals was seen to be significantly altered by only small changes in the chemical structure of the drug compound. A range of physical properties were, however, obtained with higher solubilities produced especially using amides as co-formers.