Technological study of kaolinitic clays from Fms. Escucha and Utrillas to be used in dermo-pharmaceutical products

The present study aims to evaluate five clay samples from different pits in the Teruel province, Spain. While these clays are primarily utilized as raw materials in ceramics, their potential applications in pharmaceutical and cosmetic domains, notably in sun protection and thermal mud products, are under investigation. Characterization of these clays entailed X-ray diffraction, X-ray fluorescence, scanning electron microscopy, pH measurement, analysis of technological properties, rheological assessment, and thermal property evaluation. Furthermore, given the predominant composition of kaolin in most of the samples, their Sun Protection Factor (SPF) in suspensions and physical stability were assessed. The studied samples exhibited varied mineralogical compositions, primarily consisting of kaolinite (70% to 15%), quartz (75% to 5%), and illite (26% to 7%). The pH values of these dispersions closely matched the skin's pH, exhibiting anti-thixotropic behavior at 50% w/w and demonstrating suitable viscosity for skin application. Based on their composition and rheological properties, the samples exhibited potential for use as therapeutic thermal muds. Analyses of cooling kinetics were performed to validate this potential. Results showed that the dispersions systems attained temperatures between 33.89 ◦C and 34.62 ◦C within 20 min (the common application time for thermal muds) and reached 32 ◦C (skin temperature) in 24.3 to 26.22 min, confirming their appropriateness as therapeutic muds. The SPF values of the dispersions varied from 7.46 to 16.65, with the majority of samples showing significant stability during 45 h. Consequently, it can be inferred that most of the studied samples show advantageous characteristics for inclusion in topical formulations, especially in sun protection and thermal mud products

Thixotropic Hydrogels Based on Laponite® and Cucurbituril for Delivery of Lipophilic Drug Molecules

Nowadays the use of hydrogels for biomedical purposes is increasing because of their interesting features that allow the development of targeted drug delivery systems. Herein, hydrogel based on Laponite (R) (Lap) clay mineral as gelator and cucurbit[6]uril (CB[6]) molecules were synthetized for the delivery of flufenamic acid (FFA) for potential topical application. Firstly, the interaction between CB[6] and FFA was assessed by UV-vis spectroscopic measurements and molecular modeling calculations. Then, the obtained complex was used as filler for Lap hydrogel (Lap/CB[6]/FFA). The properties of the hydrogel in terms of viscosity and, self-repair abilities were investigated; its morphology was imaged by scanning electron and polarized optical microscopies. Furthermore, the changes in the hydrodynamic radii and in the colloidal stability of CB[6]/Lap mixture were investigated in terms of translational diffusion from dynamic light scattering and zeta-potential measurements. Finally, the kinetic in vitro release of FFA, from Lap/CB[6]/FFA hydrogel, was studied in a medium mimicking the pH of skin and the obtained results were discussed both by an experimental point of view and by molecular modeling calculations.The use of hydrogels for biomedical purposes is increasing because of their interesting features that allow the development of targeted drug delivery systems. Herein, hydrogel based on Laponite (R) (Lap) clay mineral as gelator and cucurbit[6]uril (CB[6]) molecules were synthetized for the delivery of flufenamic acid (FFA) for potential topical application.imag