Co-crystallization is a promising approach to improving both the solubility and the dissolution rate of active pharmaceutical ingredients. Crystal structure determination from powder diffraction data plays an important role in determining co-crystal structures, especially those generated by mechanochemical means. Here, two new structures of pharmaceutical interest are reported: a 1:1 co‑crystal of furosemide with urea formed by liquid-assisted grinding and a second polymorphic form of a 1:1 co‑crystal of carbamazepine with indomethacin, formed by solvent evaporation. Energy minimization using dispersion-corrected density functional theory was used in finalizing both structures. In the case of carbamazepine:indomethacin, this energy minimization step was essential in obtaining a satisfactory final Rietveld refinement.

Background/Objectives: Thymoquinone (TQ) exhibits diverse biological activities, but its poor solubility and bioavailability limit its cancer efficacy, requiring innovative solutions. This study explores the development of an oral delivery system targeting colon cancer based on TQ pectin beads (TQ-PBs) produced through an adjustable electrospray technique. This study hypothesised that adjusting bead diameter through the electrospray technique enables precise control over water absorption and erosion rates, thereby achieving a controlled release profile for encapsulated TQ, which enhances targeted delivery to the colon. Methods: TQ-PBs were synthesised and optimised using an electrospray technique based on the ionic gelation method. The prepared beads were characterised based on particle size, sphericity, encapsulation efficiency (EE), water uptake, erosion, surface morphology, molecular interactions, and texture. The cumulative TQ release studies, an accelerated stability test, and cytotoxicity evaluation against the colon cancer HT-29 cell line were also assessed. Results: The optimised TQ-PB formulation demonstrated an average bead size of 2.05 ± 0.14 mm, a sphericity of 0.96 ± 0.05, and an EE of 90.32 ± 1.04%. The water uptake was 287.55 ± 10.14% in simulated gastric fluid (SGF), 462.15 ± 12.73% in simulated intestinal fluid (SIF), and 772.41 ± 13.03% in simulated colonic fluid (SCF), with an erosion rate of 45.23 ± 5.22%. TQ release was minimal in SGF (8.13 ± 1.94% after 2 h), controlled in SIF (29.35 ± 3.65% after 4 h), and accelerated in SCF (94.43 ± 2.4% after 3 h). Stability studies over one month showed a size reduction of 17.50% and a 6.59% decrease in TQ content. Cytotoxicity assessments revealed significant anticancer activity of TQ-PB, with an IC50 of 80.59 ± 2.2 μg/mL. Conclusions: These findings underscore the potential of TQ-PB as an effective oral drug delivery system for targeted colorectal cancer therapy.

Introduction: Although many techniques, such as complexation and microencapsulation, are used to mask the unpleasant taste of drugs, the success of all masking processes is evaluated in the same way. To evaluate the success of a masking process, a masked formulation must pass two tests: a structural test and an in vitro in vivo test. Areas covered: This review article highlights structural evaluation and in vitro in vivo evaluation of a taste masking process. The structural evaluation has two criteria: the absence of any chemical interaction between the drug and the masking agent and the molecular distribution of drug in the network of masking agent. The in vitro in vivo section can be verified by electronic tongues, dissolution test and volunteers and it should confirm that the final product, after applying the masking process, will have a lower rank in terms of taste. Expert opinion: This critical review helps researchers and industrial partners to evaluate a taste masking process in a systematic way, leading to better understanding of taste masking process and consequently improving the efficiency of masked dosage forms whilst hindering the unpleasant taste of drugs. This will ultimately improve the quality of life of many patients.

The herein revisited 1967 attempt of structural analysis of the solid-state complex of caffeine and pyrogallol was a pioneering investigation of what today would be seen as a prototypical pharmaceutical cocrystal model system.