How good are the crystallisation methods for co-crystals? A comparative study of piroxicam

Physicochemical Characterization and <i>In Vitro</i> Dissolution Test of Quercetin-Succinic Acid Co-crystals Prepared Using Solvent Evaporation

“…Moreover, slow evaporation can be conducted at room temperature. 12,13 It has been reported that solvent evaporation was successfully conducted to produce Q-isonicotinamide cocrystals and Q-theobromine dehydrate co-crystals. 14 The present study investigated the physicochemical properties and the dissolution profile of QS co-crystals (Co-QS).…”

Intermolecular hydrogen transfer and solubility tuning in multi-component molecular crystals of the API piroxicam

“…Analysis of the ΔpKa values for the basic co-formers are in general agreement with the ΔpKa rule, but the situation may be more complex when PX exists in zwitterionic form. pKa values are generally measured using water as the solvent and in cases where zwitterionic forms are present, the transferability to different solvents may be less reliable.. Multi-component molecular crystals of CA and BA with PX resulted in salts where PX is present as a cation (PX + ) with both the hydroxyl and pyridinium N protonated (9)(10)(11)(12). This is the first time PX has been seen in the PX + form.…”

“…In the cases of PX crystallization with imidazole and chloranilic acid, the product formed was found to vary with choice of solvent or crystallisation temperature. For the PX imidazole system different solvates were formed through crystallisation from methanol (1) and also for the pair of materials crystallised from ACN at RT (2) and 50°C (3), while for PX with chloranilic acid, crystallisation from ACN at RT produced one polymorph (form I; 9), crystallisation at 40°C produced polymorphic form II (10), while crystallisation at 50°C produced a solvate (11).…”

“…Molecular complexes from cocrystallisation experiments are seen as an increasingly useful tool in the preparation of solid forms of active pharmaceutical ingredients (APIs), with molecular complexes of pharmaceuticals not only having the potential to be patented as new materials 2 , but also for improving the physicochemical properties of an API without compromising the structural integrity 3 . Piroxicam (PX) is a non-steroidal anti-inflammatory drug (NSAID) that has been extensively studied in the solid state [4][5][6][7][8][9][10][11] . Presented here are further investigations of multicomponent molecular crystals of this important API, with particular regard to the crystal engineering potential and the potential modification of relevant physical properties of the multi-component crystals formed, with respect to those of the parent material.…”

Multicomponent organic crystals at high pressure

“…Many of these systems are of practical importance, for example, for pharmaceutical industry [17][18][19][20][21][22][23][24][25], as ferroelectrics [26,27], non-linear optical materials [28,29], or as energetic materials [30,31]. At the same time, they are of great interest for basic understanding of the factors that influence the formation of crystal structures from fluid phases under different experimental conditions and their response to variations of temperature and pressure.…”