Co-crystals under the microscope

The way that a drug is formulated can have important effects on its properties. It can effect how soluble the drug is and ultimately how well it can be taken up by the body. One of the developing methods to alter the physio-chemical properties of drugs and drug-like molecules is to form co-crystals with either other molecules or with counter ions, to form salts or even to result in solid solutions. But what are co-crystals?

Co-crystals are the name given to crystals that are formed from two or more types of molecules. The structure of the molecules in the co-crystals are important for chemical properties of each of the two partners. Investigating the formation, structure and properties of co-crystals is becoming an important field in the pharmaceutical and formulation science areas.

JBL Science have a particular mass of talent to enable us to undertake detailed investigations of crystalline forms of molecules, including how the crystals form and the structure of the molecules that they contain. Our skills have been highlighted in 2 recent scientific papers published only days apart in the Royal Society of Chemistry journal CrystEngComm.

Lincoln scientists Paolo Lucaioli and Nick Blagden led a study that found a new crystalline form of succinic acid,a key molecule in the process by which our bodies generate energy.

Meanwhile, Ian Scowen was co-lead in a study that investigated the effects that different ions had on the packing of an organosulfur antibiotic compound.

The two studies show elegantly how altering the conditions under which crystals form can affect the shape of molecules and they way that they associate into crystals. Building crystallographic knowledge will ultimately lead to an ability to predict more accurately the physical and chemical properties of sold state molecules.

JBL Science's Dr Elisa Nauha, who carried out x-ray diffraction analysis for the two studies, said "its great that these two papers are in the public domain, since they demonstrate the kind of molecular detail that can be derived from x-ray diffraction. Our expertise in crystallographic analyses should be incredibly useful for a range of future studies in crystalline materials."

Links to the articles on the publishers websites appear below and reprints are available from JBL Science on request.

For more details please contact Dr. Andy Gill.

Serendipitous isolation of a disappearing conformational polymorph of succinic acid challenges computational polymorph prediction; Paolo Lucaioli, Elisa Nauha, Ilaria Gimondi, Louise S. Price, Rui Guo, Luca Iuzzolino, Ishwar Singh, Matteo Salvalaglio, Sarah L. Price and Nicholas Blagden, CrystEngComm, 2018.

Structural motifs in salts of sulfathiazole: implications for design of salt forms in pharmaceuticals APIs; Colin C. Seaton, Rayan R. Thomas, Eman A. A. Essifaow, Elisa Nauha, Tasnim Munshi and Ian J. Scowen, CrystEngComm, 2018

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