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The performance of transmission Raman spectroscopy (TRS) for quantifying a cocrystal and its dissociation in solid dosage form was investigated. Some tablets containing 0%-20% (w/w) of a cocrystal of carbamazepine (CBZ)/succinic acid (SUC), 0%-4% of CBZ, 0%-4% of SUC, and 75%-99% of D-mannitol were prepared. The Raman spectra of these tablets were preprocessed using the standard normal variate (SNV) or multiplicative scatter correction (MSC) as well as the Savitzky Golay second derivative, and then, these were used to generate calibration models using partial least squares (PLS) regression. The performance of the model was superior when the MSC preprocessing spectra of the cocrystal between 200 and 1800 cm -1 were used for calibration. The determination coefficient of the PLS calibration curve for the CBZ/SUC cocrystal between 200 and 1800 cm -1 with MSC was 0.97, root mean square error of cross validation (RMSECV) was 1.16, and root mean square error of prediction (RMSEP) was 1.10. As in the case of the CBZ/SUC cocrystal, the performance of the model was superior when the MSC preprocessing spectra of CBZ and SUC between 200 and 1800 cm -1 were used for calibration. These data suggest that TRS is useful for quantifying a cocrystal and its dissociation compounds in solid dosage forms., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Cocrystals (CCs) used in the pharmaceutical industry are defined as complex crystals formed by reaction between an API and a cocrystal former (CCF); unlike salts, CCs do not show proton transfer. Recently, pharmaceutical CCs have been used to improve the drug-likeness of APIs, such as solubility and stability. Grinding is more effective for CC synthesis than crystallization from solution because in the former case, the API can predominantly interact with the CCF without being affected by solvents. However, this method is tedious because the API is ground with only one CCF at a time. We developed a cocktail cocrystal grinding (CCG) method, in which a mixture of CCFs having the same functional group was used. No false negatives/positives were observed in CCG when carbamazepine was used as the model compound. This method could be used to obtain CCs of piroxicam and spironolactone. False negatives were observed for only one compound from among three model compounds, indicating that CCG facilitates efficient CC detection and that it has higher throughput than does the conventional method. Further, CCG is fast and suitable for rational CC screening, and it helps identify the partial structure of CCFs that forms synthons with an API., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The aim of the present study was to develop a novel solubilization technique consisting of a nano-cocrystal suspension by integrating cocrystal and nanocrystal formulation technologies to maximize solubilization over current solubilizing technologies. Monodisperse carbamazepine–saccharin, indomethacin–saccharin, and furosemide–caffeine nano-cocrystal suspensions, as well as a furosemide–cytosine nano-salt suspension, were successfully prepared with particle sizes of less than 300 nm by wet milling with the stabilizers hydroxypropyl methylcellulose and sodium dodecyl sulfate. Interestingly, the properties of resultant nano-cocrystal suspensions were dramatically changed depending on the physicochemical and structural properties of the cocrystals. In the formulation optimization, the concentration and ratio of the stabilizers also influenced the zeta potentials and particles sizes of the resultant nano-cocrystal suspensions. Raman spectroscopic analysis revealed that the crystalline structures of the cocrystals were maintained in the nanosuspensions, and were physically stable for at least one month. Furthermore, their dissolution profiles were significantly improved over current solubilization-enabling technologies, nanocrystals, and cocrystals. In the present study, we demonstrated that nano-cocrystal formulations can be a new promising option for solubilization techniques to improve the absorption of poorly soluble drugs, and can expand the development potential of poorly soluble candidates in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]