Molecular interactions and taste perception of an artificial sweetener saccharin sodium in aqueous and in aqueous solutions of choline chloride at different temperatures

Effect of artificial sweetener saccharin on lysozyme aggregation: A combined spectroscopic and in silico approach

The use of saccharin in food products attracts much attention as it involves the risk of lethal allergies and many protein aggregation diseases. However, its role in protein aggregation has not been explored to date. This study embodies the effect of artificial sweeteners on HEWL in the absence and presence of commonly available natural products such as curcumin and EGCG. Various techniques have been used to characterize the protein interaction, such as steady-state emission and time-resolved fluorescence, FTIR, gel electrophoresis, TEM, and molecular docking. Steady-state and time-resolved studies revealed the binding strength and concomitant effect of saccharin on HEWL protein. Kinetic measurements revealed that saccharin causes significant enhancement of HEWL aggregation with a considerable reduction in lag phase time i.e. from 37 hr to 08 hr. Whereas in the presence of natural products, the effect of saccharin on HEWL aggregation was significantly reduced specifically in the case of curcumin. The result obtained in the fluorescence experiment were also supported by the gel electrophoresis technique and morphological images taken by TEM. The rapid change in the secondary structure of the protein in the presence of saccharin was confirmed by the FTIR spectroscopy technique. This study is instrumental in understanding the effect of saccharin on protein aggregation and the role of commonly available natural products in curbing its effect.

Sulfonic Acid Derivatives in the Production of Stable Co-Amorphous Systems for Solubility Enhancement

Co-amorphization is a promising approach to stabilize drugs in the amorphous form. Olanzapine, a poorly water-soluble drug was used in this study. Sulfonic acids (saccharin, cyclamic acid and acesulfame), free and in salt forms, were used as co-formers and compared with carboxylic acids commonly used in the preparation of co-amorphous systems. Several manufacturing techniques were tested, and the co-amorphous systems characterized by differential scanning calorimetry, X-ray powder diffraction, thermogravimetry and Fourier-transform infrared spectroscopy. Free sulfonic acids produced co-amorphous systems with the drug, unlike their salts. Spectroscopy data suggests the formation of salts between olanzapine and the sulfonic acids, used as co-formers. The co-amorphous system produced with saccharin by solvent evaporation, showed the most notable solubility enhancement (145 times). The stability of amorphous and co-amorphous olanzapine systems was assessed upon exposure to stress conditions during storage. Amorphized olanzapine readily reconverted back to the crystalline form while sulfonic acids:olanzapine co-amorphous were stable for up to 24 weeks in low/medium humidity conditions (11-75% RH). Results highlight the potential advantages offered by sulfonic acids as co-formers to produce stable and more soluble co-amorphous olanzapine.

Molecular interaction investigation of some alkaline earth metal salts in aqueous citric acid at various temperatures by physiochemical studies

Densities, ultrasonic velocity, conductance and viscosity of some alkaline earth metal chlorides such as magnesium chloride (MgCl2) and calcium chloride (CaCl2) were calculated in the concentration range (0.01–0.12 mol kg−1) in 0.01 mol kg−1 aqueous solution of citric acid (CA + H2O) at four varying temperatures T 1 = 303.15 K, T 2 = 308.15 K, T 3 = 313.15 K and T 4 = 318.15 K. The parameters like apparent molar volume (ϕ v ), limiting apparent molar volume ( ϕ v o ${\phi }_{v}^{o}$ ) and transfer volume (Δtr ϕ v o ${\phi }_{v}^{o}$ ) were calculated from density data. Viscosity data have been employed to calculate Falkenhagen coefficient (A), Jone–Dole’s coefficient (B), relative viscosity (η r ), and relaxation time (τ) whereas limiting molar conductance ( Λ m o ${{\Lambda}}_{m}^{o}$ ) has been evaluated from conductance studies. Using these parameters, various type of interactions occurred in the molecules have been discussed. Values of Hepler’s constant (d 2 ϕ v o ${\phi }_{v}^{o}$ /dT 2) p , (dB/dT) and d( Λ m o ${{\Lambda}}_{m}^{o}$ η o )/dT suggests that both MgCl2 and CaCl2 behave as structure breaker in (CA + H2O) system. The positive value of transfer volume exclusively tells about solute–solvent interactions which further indicate that both metal chlorides distort the structure of water and act as structure breaker. These studies are helpful in understanding the nature of interactions occurs in biological systems as CA and metal salts are essential for normal functioning of body.