Solubility of Sulfamethazine in the Binary Mixture of Acetonitrile + Methanol from 278.15 to 318.15 K: Measurement, Dissolution Thermodynamics, Preferential Solvation, and Correlation

Solubility of sulfamethazine (SMT) in acetonitrile (MeCN) + methanol (MeOH) cosolvents was determined at nine temperatures between 278.15 and 318.15 K. From the solubility data expressed in molar fraction, the thermodynamic functions of solution, transfer and mixing were calculated using the Gibbs and van ’t Hoff equations; on the other hand, the solubility data were modeled according to the Wilson models and NRTL. The solubility of SMT is thermo-dependent and is influenced by the solubility parameter of the cosolvent mixtures. In this case, the maximum solubility was achieved in the cosolvent mixture w0.40 at 318.15 K and the minimum in pure MeOH at 278.15 K. According to the thermodynamic functions, the SMT solution process is endothermic in addition to being favored by the entropic factor, and as for the preferential solvation parameter, SMT tends to be preferentially solvated by MeOH in all cosolvent systems; however, δx3,1<0.01, so the results are not conclusive. Finally, according to mean relative deviations (MRD%), the two models could be very useful tools for calculating the solubility of SMT in cosolvent mixtures and temperatures different from those reported in this research.

Solubility of Cinnarizine in (Transcutol + Water) Mixtures: Determination, Hansen Solubility Parameters, Correlation, and Thermodynamics

Between 293.2 and 313.2 K and at 0.1 MPa, the solubility of the weak base, cinnarizine (CNZ) (3), in various {Transcutol-P (TP) (1) + water (2)} combinations is reported. The Hansen solubility parameters (HSP) of CNZ and various {(TP) (1) + water (2)} mixtures free of CNZ were also predicted using HSPiP software. Five distinct cosolvency-based mathematical models were used to link the experimentally determined solubility data of CNZ. The solubility of CNZ in mole fraction was increased with elevated temperature and TP mass fraction in {(TP) (1) + water (2)} combinations. The maximum solubility of CNZ in mole fraction was achieved in neat TP (5.83 × 10−2 at 313.2 K) followed by the minimum in neat water (3.91 × 10−8 at 293.2 K). The values of mean percent deviation (MPD) were estimated as 2.27%, 5.15%, 27.76%, 1.24% and 1.52% for the “Apelblat, van’t Hoff, Yalkowsky–Roseman, Jouyban–Acree, and Jouyban–Acree–van’t Hoff models”, respectively, indicating good correlations. The HSP value of CNZ was closed with that of neat TP, suggesting the maximum solubilization of CNZ in TP compared with neat water and other aqueous mixtures of TP and water. The outcomes of the apparent thermodynamic analysis revealed that CNZ dissolution was endothermic and entropy-driven in all of the {(TP) (1) + water (2)} systems investigated. For {(TP) (1) + water (2)} mixtures, the enthalpy-driven mechanism was determined to be the driven mechanism for CNZ solvation. TP has great potential for solubilizing the weak base, CNZ, in water, as demonstrated by these results.

Characterisation of pH-shift-produced protein isolates from sago palm weevil (Rhynchophorus ferrugineus) larvae

Farm-raised sago palm weevil (Rhynchophorus ferrugineus) larvae (SPWL) can be used as a protein source for food sustainability. This study aimed to investigate the potential of pH-shift processing as a cold refinery approach to produce protein isolate from SPWL. Maximum solubility of SPWL protein was observed at pH 2.0 (acid-aided process) and pH 11.5 (alkaline-aided process). The zeta-potential of the protein solution was close to zero with the lowest solubility at pH 4.5. So, the protein precipitation was performed at this pH. Although both acid and alkaline methods yielded roughly 66% protein, their nutritional and techno-functional features differed based on the pH-shifting process. The alkaline-produced protein isolate had higher essential amino acid (EAA) content and EAA index but it was darker in colour. The acid-produced protein isolate had larger levels of umami-taste-active and functional amino acids, as well as a higher emulsifying capability.

APPLICATION OF LIQUISOLID TECHNIQUE FOR ENHANCEMENT OF DISSOLUTION OF WATER INSOLUBLE DRUG CHOLECALCIFEROL

The issue of low solubility and bioavailability poses a significant challenge for most of the drug candidates for oral delivery. Liquisolid, a recently evolved technique for dissolution enhancement, can dodge these barriers. The purpose of this research was to increase the solubility of poorly soluble drug cholecalciferol by liquisolid technique. The cholecalciferol’s solubility studies were performed in a mixture of Polysorbate 80 and PEG 400 in different ratios (1:1, 1:2, 2:1, 1:3, and 3:1). Maximum solubility was observed in a 1:2 ratio. There were changes in the X-ray diffractogram and shifting of the endothermic peak in DSC from 85oC to 146oC, which indicated the drug’s conversion into an amorphous form. The liquisolid form was adsorbed on the carrier material and compressed. The optimization was done by using Plackett Burman Design with Design-Expert software. It was observed that the drugs release profile of the optimized formulation was better than the generic product and was comparable to Divisun tablets 2000 I.U (Innovator).

Fabrication of Carbamazepine Cocrystals: Characterization, In Vitro and Comparative In Vivo Evaluation

Carbamazepine (CBZ) is an antiepileptic drug having low bioavailability due to its hydrophobic nature. In the current study, efforts are made to investigate the effect of dicarboxylic acid coformer spacer groups (aliphatic chain length) on physicochemical properties, relative humidity (RH) stability, and oral bioavailability of CBZ cocrystals. Slurry crystallization technique was employed for the preparation of CBZ cocrystals with the following coformers: adipic (AA), glutaric (GA), succinic (SA), and malonic acid (MA). Powder X-ray diffractometry and Fourier-transform infrared spectroscopy confirmed cocrystal preparation. Physicochemical properties, RH stability, and oral bioavailability of cocrystals were investigated. Among the prepared cocrystals, CBZ-GA showed maximum solubility as well as improved dissolution profile (CBZ-GA > CBZ-MA > CBZ-AA > pure CBZ > CBZ-SA) in ethanol. Maximum RH stability was shown by CBZ-AA, CBZ-SA, and CBZ-MA. In vivo studies confirmed boosted oral bioavailability of cocrystals compared to pure CBZ. Furthermore, in vivo studies depicted the oral bioavailability order of cocrystals as CBZ-GA > CBZ-MA > Tegral® > CBZ-AA > CBZ-SA > pure CBZ. Thus, pharmaceutical scientists can effectively employ cocrystallization technique for tuning physicochemical properties of hydrophobic drugs to achieve the desired oral bioavailability. Overall, results reflect no consistent effect of spacer group on physicochemical properties, RH stability, and oral bioavailability of cocrystals.

Change in matrix saturation with alloying elements at primary thermocyclic processing of 44NKhTYu alloy

The total solubility of alloying elements (chromium, titanium, aluminum) in the iron-nickel matrix (Fe – Ni) of 44NKhTYu alloy, depending on the number of cycles, does not occur during primary thermocycling processing (TCP). This is evidenced by the main replicas of the matrix with (111) reflection plane indexes of the samples X-ray images under the studied modes of thermocyclic processing. The maximum solubility of alloying elements is achieved only at total quenching. Special attention should be paid to the third and fourth cycles in the further study of TCP changing the cooling rate in these cycles due to the cooling medium, since with an increase in the number of cycles in the primary TCP, significant changes do not occur.

SUPERCRITICAL EXTRACTION OF LYOPHILIZED STRAWBERRY ANTHOCYANINS WITH PULSED ELECTRIC FIELDS PRETREATMENT

The lyophilized strawberry anthocyanins were extracted using a supercritical extraction (SE) process. The effect of pulsed electric fields (PEF) as pretreatment and the influence of the addition of ethanol as a cosolvent on the percentage of extraction yield (EY) and the total anthocyanin concentration (TAC) were analyzed. The effect of PEF was evaluated at 0.5 and 1.0 kV/cm, while the effect of the cosolvent was studied in mixtures of supercritical carbon dioxide - ethanol (SCCO2 + ethanol) at 1.6 and 3.3% by weight. The best results (% EY = 0.506, TAC = 0.428 g /100 g of lyophilized strawberry) were obtained with a PEF pretreatment of 1.0 kV cm-1, 3.3%wt. ethanol at 200 bar and 333.15 K. The experimental results of solubility were suitably adjusted with the Kumar and Johnston model. The maximum solubility (0.114 g/100 g of solvent mixture) was obtained at 300 bar and 313.15 K.

Solubility of CO2 in molten Li2Co3-LiCl

Solubility of CO2 in molten Li2CO3-LiCl was measured by using a pressure differential method and the enthalpy change of the solution was calculated on that basis. The relationships between the solubility and the enthalpy change, and the temperature and the composition of the melts were discussed. The results showed that when the temperature was 873-923K and the Li2CO3content was 10-50 mol%, the solubility of CO2 increased with decreasing temperature and/or increasing Li2CO3 content.The maximum solubility was 3.965 ? 10?7gCO2/gmelt at 873Kwhen the content of Li2CO3 was 50 mol%. The solution of CO2was exothermic. With increasing temperature and Li2CO3content,more enthalpy was needed for CO2 solution.

Solubilization, Hansen Solubility Parameters, Solution Thermodynamics and Solvation Behavior of Flufenamic Acid in (Carbitol + Water) Mixtures

The solubilization, solution thermodynamics, solvation behavior and Hansen solubility parameters (HSPs) of an anti-inflammatory medicine flufenamic acid (FFA) in various Carbitol + water mixtures were evaluated in this study. The experimental solubility of FFA in mole fraction (xe) was measured at T = 298.2–318.2 K and p = 0.1 MPa using a static equilibrium method. The xe values of FFA in various Carbitol + water mixtures were correlated with van’t Hoff, Apelblat, Yalkowsky–Roseman, Jouyban–Acree and Jouyban–Acree–van’t Hoff models. All the studied models showed good correlation with mean error values of less than 2%. The xe value of FFA was found to increase significantly with the increase in temperature and Carbitol mass fraction in all Carbitol + water mixtures evaluated. The maximum and minimum xe values of FFA were recorded in pure Carbitol (2.81 × 10−1) at T = 318.2 K and pure water (5.80 × 10−7) at T = 298.2 K, respectively. Moreover, the HSP of FFA was found to be more closed with that of pure Carbitol, indicating the maximum solubility of FFA in pure Carbitol. The estimated values of activity coefficients showed higher molecular interactions in FFA–Carbitol combinations compared with FFA–water combinations. Thermodynamic studies indicated an endothermic and entropy-driven dissolution of FFA in all Carbitol + water mixtures. The solvation behavior of FFA was observed as enthalpy driven in all Carbitol + water combinations evaluated.

Formulation-Development and Evaluation of Polysorbate-Phospholipid Mixed Micelles of Piperine Loaded with Azithromycin

The overall goal of this paper was to develop polysorbate-phospholipid micelles of piperine loaded with azithromycin, and to study the effect and mechanisms enhancing the oral bioavailability of piperine and also to inhibit the bacterial growth. For the preparation of polysorbate-phospholipid-piperine mixed micelles loaded with a drug, polysorbate and phospholipid were optimized. Polysorbate concentration at 5.5% w/v showed the maximum solubility of piperine which was just similar to 5.0% w/v CMC value so, from such studies, it was confirmed that optimum concentration of polysorbate 80 required for maximum solubilization of piperine was 5.5% w/v. The maximum CMC of polysorbate 80 and phospholipid was found in batch F3 i.e. 62.4414 and 83.1122, respectively. Based on the optimization of phospholipid and polysorbate 80, three final batches were selected as the best batch i.e. F2, F3, and F4 (1:10:4, 1:15:4 and 1:20:4, respectively) for final formulation. In the formulation, maximum solubility was found in batch F3 i.e. 11.3057 mg/ml. The size of the nanoformulations was found to be 0.3396 r.nm by using zeta analyzer. The drug release was determined in 0.1 N HCl at 5, 10, 15, 30 and 60 min. Further, 7.4 pH phosphate was added and release was determined at 30, 60, 120, 180 and 240 min. It was noted that formulation F3 has maximum drug content and F1 was found as maximum entrapment efficiency. The maximum drug release was found in the formulation F3. The approach of using phospholipid nanoformulations loaded with azithromycin showed antibacterial activity in the nutrient agar plate. These formulations prevent the visual growth of bacteria. It was shown that the maximum zone of inhibition was found at the concentration of 100mg/ml. The MIC endpoint at the lowest concentration of formulation at which there is minimum visual growth around the dice was found to be 50 mg/ml.