Lovastatin crystals often exhibit an undesirable needle-like morphology. Several studies have shown how a needle-like morphology can be modified in antisolvent crystallisation with the use of additives, but there is much less experimental work demonstrating crystal shape modification without the use of additives. In this study, a series of unseeded continuous antisolvent crystallisation experiments were conducted with the process conditions of supersaturation, total flow rate, and ultrasound level being varied to determine their effects on crystal size and shape. This experimental work involved identifying acetone/water as the most suitable solvent/antisolvent system, assessing lovastatin nucleation behaviour by means of induction time measurements, and then designing and implementing the continuous antisolvent crystallisation experiments. It was found that in order to produce the smallest and least needle-like particles, the maximum total flow rate and supersaturation had to be combined with the application of ultrasound. These results should aid development of pharmaceutical manufacturing processes where the ability to control particle size and shape would allow for optimisation of crystal isolation and more efficient downstream processing.

Single crystals of 2D coordination network {Cu 2 L 2 • (DMF) 3 (H 2 O) 3 } n (1-DMF) were prepared by reaction of commercial reagents 3-formyl-4-hydroxybenzoic acid (H 2 L) and Cu(NO 3 ) 2 in dimethylformamide (DMF). The single-crystal structure shows two distinct Cu(II) coordination environments arising from the separate coordination of Cu(II) cations to the carboxylate and salicylaldehydato moieties on the linker, with 1D channels running through the structure. Flexibility is exhibited on solvent exchange with ethanol and tetrahydro-furan, while porosity and the unique overall connectivity of the structure are retained. The activated material exhibits type I gas sorption behaviour and a BET surface area of 950 m 2 g À 1 (N 2 , 77 K). Notably, the framework adsorbs negligible quantities of CH 4 compared with CO 2 and the C 2 H n hydrocarbons. It exhibits exceptional selectivity for C 2 H 2 /CH 4 and C 2 H 2 /C 2 H n , which has applicability in separation technologies for the isolation of C 2 H 2 .[a] M.

Changes in temperature can significantly affect spectroscopic-based methods for in situ monitoring of processes. As varying temperature is inherent to many processes, associated temperature effects on spectra are unavoidable, which can hinder solute concentration determination. Ultraviolet (UV) and mid-infrared (IR) data were acquired for l-ascorbic acid (LAA) in MeCN/H2O (80:20 w/w) at different concentrations and temperatures. For both techniques, global partial least squares (PLS) models for prediction of LAA concentration constructed without preprocessing of the spectra required a high number of latent variables to account for the effects of temperature on the spectra (root mean square error of cross validation (RMSECV) of 0.18 and 0.16 g/100 g solvent, for UV and IR datasets, respectively). The PLS models constructed on the first derivative spectra required fewer latent variables, yielding variable results in accuracy (RMSECV of 0.23 and 0.06 g/100 g solvent, respectively). Corresponding isothermal local models constructed indicated improved model performance that required fewer latent variables in the absence of temperature effects (RMSECV of 0.01 and 0.04 g/100 g solvent, respectively). Temperature correction of the spectral data via loading space standardization (LSS) enabled the construction of global models using the same number of latent variables as the corresponding local model, which exhibited comparable model performance (RMSECV of 0.06 and 0.04 g/100 g solvent, respectively). The additional chemometric effort required for LSS is justified if prediction of solute concentration is required for in situ monitoring and control of cooling crystallization with an accuracy and precision approaching that attainable using an isothermal local model. However, the model performance with minimal preprocessing may be sufficient, for example, in the early phase development of a cooling crystallization process, where high accuracy is not always required. UV and IR spectrometries were used to determine solubility diagrams for LAA in MeCN/H2O (80:20 w/w), which were found to be accurate compared to those obtained using the traditional techniques of transmittance and gravimetric measurement. For both UV and IR spectrometries, solubility values obtained from models with LSS temperature correction were in better agreement with those determined gravimetrically. In this first example of the application of LSS to UV spectra, significant improvement in the predicted solute concentration is achieved with the additional chemometric effort. There is no extra experimental burden associated with the use of LSS if a structured approach is employed to acquire calibration data that account for both temperature and concentration.

In the copper–mefenamate complex tetrakis[μ-2-(2,3-dimethylanilino)benzoato-κ2 O:O′]bis[aquacopper(II)]–1-methoxy-2-(2-methoxyethoxy)ethane (1/2), [Cu2(C15H14NO2)4(H2O)2]·2C6H14O3, the asymmetric unit comprises a CuII cation coordinated to two mefenamate ligands solvated with a water molecule and a diglyme molecule. The complex adopts a paddlewheel motif and is compared to structural analogues crystallized with dimethylformamide and dimethyl sulfoxide.