Sahand University of Technology

The Active Pharmaceutical Ingredient (APIs) selected were Artemether, Lumefantrine, Avobenzone and Ensulizole. The IUPAC names (3R,5aS,6R,8aS,9R,10S,12R,12aR)-Decahydro-10-methoxy-3,6,9-trimethyl-3,12-epoxy-12H-pyrano[4,3-j]-1,2-benzodioxepin for Artemether, 2-(dibutylamino)-1-[(9Z)-2,7-dichloro-9-[(4-chlorophenyl)methylidene]fluoren-4-yl]ethanol for Lumefantrine, 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl) propane-1,3-dione for Avobenzone and 2-phenylbenzimidazole-5-sulfonic acid for Ensulizole respectively. Artemether and Lumefantrine are used to cure malarial infections caused by parasite Plasmodium falciparum. Avobenzone and Ensulizole are oil-soluble, sun-screen ingredients used to absorb and block harmful UVA rays, thus protecting the skin from sun damage. The APIs vary substantially in polarity in which Artemether is the least polar and Ensulizole being the most polar in nature. HPTLC used for determination was CAMAG Linomat V semi-automatic sample applicator with CAMAG TLC scanner 3 and CATS software for interpretation of data. The stationary phase used was TLC aluminium plates precoated with silica gel 60F 254. The double development approach was employed to improve resolution and peak symmetry among closely eluting APIs. In the first development, methanol was used as the mobile phase followed by a second development using a clear solvent mixture of Toluene: Ethyl acetate: Methanol: Formic acid in a ratio of (6:4:0.1:1). The APIs were dissolved in their respective suitable solvents such that a concentration of 1000 ppm of each API was obtained. A solution of 2.0μl of each API was loaded by using the applicator in which nitrogen was used as a carrier gas that applicators need for this purpose. After the sample application, the plate was kept in Twin Through Chamber (TTC) which was previously saturated with the mobile phase for 20 minutes. The plate was run till the solvent front. It was dried with a dryer before scanning it under the UV lamp. The corresponding spots were observed except for Artemether. The spot corresponding to Artemether was observed after treating it with Anisaldehyde sulphuric acid as a derivatising agent. It was, thus, possible to establish simultaneous determination of Rf values of all the four APIs with a single mobile phase. This will help in the simultaneous quantitative determination of these API formulations and in forced degradation studies and identification of impurities by TLC- Mass spectroscopy.

ABSTRACT Isinglass/agar hydrogel beads were synthesized using a self‐assembly method at a water‐in‐oil emulsion interface. The hydrogel was chemically crosslinked using glutaraldehyde to generate stable aldimine bonds with amino (–NH 2 ) groups present in isinglass. Fourier‐transform infrared spectroscopy (FTIR) was utilized to determine the generation of chemical crosslinks within the hydrogel. The hydrogel's porous and interconnected three‐dimensional morphology was investigated with field emission scanning electron microscopy (FE‐SEM). The resulting hydrogel beads demonstrated a narrow and uniform size distribution ranging from 3.5 to 3.75 mm, confirming the reproducibility of the synthesis method. The equilibrium swelling ratio was reduced as the crosslinking agent concentration increased, resulting in water uptake decreasing from about 1358% to 753%. Also, the swelling ratio was very sensitive to pH changes, showing a maximum (~1580%) at pH 3 and decreasing as pH increased. The swelling ratio increased with the temperature, reaching approximately 1960% at 60°C. Analysis of the swelling kinetics showed that the swelling behavior was in good agreement with the pseudo‐second‐order model, implying the presence of chemical interactions between the polymeric chains and the molecules of water. These findings suggest that these hydrogels could be suitable for wastewater treatment, contaminant removal, or controlled release.

Urban tunnel construction often faces challenges due to weak ground conditions or shallow overburden, making effective stabilization of surrounding soil critical. Selecting an appropriate excavation method is essential for controlling ground subsidence and convergence, which are key considerations in tunnel design, especially in densely populated areas. Excavation-induced ground movements can propagate upward, potentially causing surface subsidence and structural damage. Therefore, a systematic decision-making framework is indispensable during the design phase. This study presents a comprehensive model for selecting the optimal excavation method for Phase 4 of Tehran Metro Line 3. The model evaluates a wide range of criteria, including technical, financial, managerial, social, and geo-mechanical factors. Seven candidate alternatives were considered: Open Shield (full face) method, Slurry method, NATM (New Austrian Tunneling Method), fore-poling, twin-tunnel excavation with TBM, EPB (Earth Pressure Balance) Shield method, and Open Trench method. The Analytical Hierarchy Process (AHP) was applied to derive criteria weights, and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was employed to rank alternatives. Both methods consistently identified Alternative E as the most suitable excavation method. The proposed framework provides a robust and systematic approach that can be applied to future metro tunneling projects, ensuring informed decision-making under complex technical and environmental constraints.