Low physical stability is the limitation of the widespread use of amorphous drugs. The co-amorphous drug system is a new and emerging method for preparing a stable amorphous form. Co-amorphous is a single-phase amorphous multicomponent system consisting of two or more small molecules that are a combination of drugs or drugs and excipients. The co-amorphous system that uses benzoic acid (BA) as an excipient was studied to improve the physical stability, dissolution, and solubility of desloratadine (DES). In this study, the co-amorphous formation of DES and BA (DES–BA) was prepared by melt-quenching method and characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and polarized light microscopy (PLM). Dissolution, solubility, and physical stability profiles of DES–BA were determined. The DES crystals were converted into DES–BA co-amorphous form to reveal the molecular interactions between DES and BA. Solid-state analysis proved that the co-amorphous DES–BA system (1:1) is amorphous and homogeneous. The DSC experiment showed that the glass transition temperature (Tg) of tested DES–BA co-amorphous had a higher single Tg compared to the amorphous DES. FTIR revealed strong interactions, especially salt formation. The dissolution rate and solubility of co-amorphous DES–BA (1:1) obtained were larger than the DES in crystalline form. The PXRD technique was used to assess physical stability for three months at 40 °C with 75% RH. The DES–BA co-amorphous system demonstrated better physical stability than a single form of amorphous DES. Co-amorphous DES–BA has demonstrated the potential for improving solid-state stability, as the formation of DES–BA co-amorphous salt increased solubility and dissolution when compared to pure crystalline DES. This study also demonstrated the possibility for developing a DES–BA co-amorphous system toward oral formulations to improve DES solubility and bioavailability.

The aim of this study was to investigate the acute and subchronic toxicity of a film formulation that combines κ-Carrageenan and konjac glucomannan for soft capsule application. For the acute toxicity study, a dose of 2000 mg/kg body weight (bw) of the film suspension was administered orally to rats. The animals were observed for toxic symptoms and mortality daily for 14 days. In a subchronic toxicity study, the film suspension, at doses of 10, 30 and 75 mg/kg bw for 28 days, were orally administered to rats. After 28 days, the rats were sacrificed for hematological, biochemical and histological examination. In the acute toxicity study, neither signs of toxicity nor death among the rats were observed for up to 14 days of the experimental period. The results of the subchronic toxicity study show that there were no significant changes observed in the hematology and organ histology. Some alterations to the relative organ weight and blood biochemistry were observed, but they were considered to be temporary effects and not an indication of toxic effects. The overall findings of this study indicate that the film formulation of κ-Carrageenan and konjac glucomannan is non-toxic up to a dose of 75 mg/kg bw, which could be considered a safe dose for soft capsule application.

Carboxylic acid–pyridine heterosynthon (CPHS) is one of the most common synthons found in cocrystal packing. Phenylacetic acid (PYC)–nicotinamide (NIC) (PYCNIC) cocrystals were used as a computational model to assess the most important factor in the emergence of the synthon. Geometry optimization was carried out on every possible two molecules of PYC–NIC conformation based on B3LYP-D3BJ/6-311G (d,p). Various energetic parameters, including total energy, interaction energy, and hydrogen bond energy, were used to compare the existing conformation to the putative conformation. The conformation with CPHS has −53.87 kJ mol⁻¹ of single intermolecular hydrogen bond energy (EHB), which is the strongest of all. It turns out that there is no other parameter better than EHB to describe the superiority of CPHS in PYCNIC.