No abstract

No abstract

Microemulsion (ME) is a micron-sized droplet that consists of oil and water, with addition of a surfactant and cosurfactant. Recently, ME is widely used in biomedical application for proper drug delivery in the human body. Castor oil as the oil phase, Tween 80 or Tween 20 as the surfactant, glycerol or ethanol as the cosurfactant, and DI water as the water phase were used for ME preparation in this study. The effect of the surfactant-to-cosurfactant ratio on the pseudoternary phase diagram was investigated. The as-synthesized ME with the composition of 5 wt.% castor oil, 85 wt.% surfactant mixture, and 10 wt.% water was characterized based on its particle size, polydispersity index, and zeta potential. From that composition, the largest ME was attained at an S mix 2 weight ratio of tween 80 to ethanol. Astaxanthin as lipophilic drug substance was used as the model drug for the ME encapsulation study. The thermal and storage analysis test of ME and astaxanthin-loaded ME demonstrated the stability of the assynthesized ME and its analogous drug-loaded form.

A greener route to synthesize mesoporous copper–gallic acid metal–organic framework (CuGA MOF) than the conventional method using harmful DMF solvent was proposed in this study. Various synthesis attempts were conducted by modifying the synthesis conditions to produce CuGA MOF with comparable physical properties to a reference material (DMF-synthesized CuGA NMOF). The independent variables investigated include the molar ratio of NaOH to GA (1.1 to 4.4) and the synthesis temperature (30, 60, 90 °C). It was found that proper NaOH addition was crucial for suppressing the generation of copper oxide while maximizing the formation of CuGA MOF. On the other hand, the reaction temperature mainly affected the stability and adsorption potential of CuGA MOF. Reacting Cu, GA, and NaOH at a molar ratio of 1:1:2.2 and a temperature of 90 °C, produced mesoporous MOF (CuGA 90–2.2) with a surface area of 198.22 m2/g, a pore diameter of 8.6 nm, and a thermal stability of 219 °C. This MOF exhibited an excellent adsorption capacity for the removal of methylene blue (124.64 mg/g) and congo red (344.54 mg/g). The potential usage of CuGA 90–2.2 as a reusable adsorbent was demonstrated by its high adsorption efficiency (> 90%) after 5 adsorption–desorption cycles.