Zeolites as Ingredients of Medicinal Products.

Development of new medicinal products for particular therapeutic treatment or for better manipulations with better quality and less side effects are possible as a result of advanced inorganic and organic materials application, among which zeolites, due to their properties and versatility, have been gaining attention. This paper is an overview of the development in the use of zeolite materials and their composites and modifications as medicinal products for several purposes such as active agents, carriers, for topical treatments, oral formulations, anticancer, the composition of theragnostic systems, vaccines, parenteral dosage forms, tissue engineering, etc. The objective of this review is to explore the main properties of zeolites and associate them with their drug interaction, mainly addressing the advances and studies related to the use of zeolites for different types of treatments due to their zeolite characteristics such as molecule storage capacity, physical and chemical stability, cation exchange capacity, and possibility of functionalization. The use of computational tools to predict the drug-zeolite interaction is also explored. As conclusion was possible to realize the possibilities and versatility of zeolite applications as being able to act in several aspects of medicinal products.

Can We Form Mesoporous Zeolites by Steam Assisted Crystallization of MCM-41?

The possibility of crystallizing silicalite-1 (MFI) from the pore walls of as-synthesized MCM-41 via steam-assisted crystallization (SAC) was thoroughly investigated. A kinetic study was conducted through the impregnation of as-synthesized MCM-41 with the structure-directing agent tetrapropyl-ammonium hydroxide (TPAOH). Materials obtained after different SAC treatment times (1−288 h) were characterized by XRD, nitrogen physisorption at 77 K, TGA/DTA, and SEM. The achieved results allowed us to conclude that during SAC treatment, rapid destruction of the hexagonal mesophase occurs with the enlargement of mesopores, probably by their coalescence, until achieving non-porous amorphous silica. Only thereafter is the crystallization of the MFI phase evidenced through the development of micron-sized (>10 µm) MFI structured crystals. This study suggests the probable practical impossibility of even partial crystallization of the pore walls of mesoporous materials by SAC.

Study of Faujasite zeolite as a modified delivery carrier for isoniazid.

The adsorption of isoniazid in the Faujasite zeolite channels has been studied. For that, the influence of the pH from the solution media in the adsorption process was verified to enable higher amount of isoniazid retained. With the information of the best pH and the equilibrium time obtained with the kinetic study, an isotherm was constructed and the hybrid material obtained with the plateau concentration equilibrium was characterized with several techniques. Molecular modeling calculations were also performed for a better understanding of the adsorption process and how the interaction between zeolite and isoniazid occurs. The geometrical disposition of the drug molecules into the zeolite channels, the saturation levels, the different isoniazid protonation states with respect to the pH media and the interaction energy between the zeolite surface and the isoniazid molecule was studied. Finally, a drug release study was made to verify if the Faujasite-Y zeolite could change the isoniazid release in acid and phosphate buffer media. The results show that the Faujasite-Y has the possibility to work as carrier for isoniazid, where the adsorption process is more effective in media at pH 3, result confirmed by the molecular modeling. The isoniazid release essay showed that the hybrid material does not change the drug release profile, provides more stability in acid media, indicating that the zeolite can be used as carrier for isoniazid, and improve the medicine formulations on antituberculosis treatment.

Natural Inorganic Ingredients in Wound Healing.

BACKGROUND: One of the major clinical challenges is to achieve a rapid and efficient treatment of complex chronic wounds. Nowadays, most wound dressings currently available are unable to find a solution to the challenges of resistance to bacterial infection, protein adsorption and increased levels of exudates. Natural inorganic ingredients (clay minerals, metal cations, zeolites, etc.) could be the key to solve the problem satisfactorily. Some of these materials have shown biocompatibility and ability to enhance cell adhesion, proliferation and cellular differentiation and uptake. Besides, some natural inorganic ingredients effectively retain drugs, allowing the design of drug delivery matrices. OBJECTIVE: Possibilities of natural inorganic ingredients in wound healing treatments have been reviewed, the following sections have been included: 1. Introduction 2. Functions of Inorganic Ingredients in wound healing 2.1. Antimicrobial effects 2.2. Hemostatic effects 3. Clay minerals for wound healing 3.1. Clay minerals 3.2. Clay mineral semisolid formulations 3.3. Clay/polymer composites and nanocomposites 3.4. Clay minerals in wound dressings 4. Other inorganic materials for wound healing 4.1. Zeolites 4.2. Silica and other silicates 4.3. Other minerals 4.4. Transition metals 5. Conclusion. Conclusion: Inorganic ingredients possess useful features for the development of chronic wounds advanced treatments. They improve physical (mechanical resistance and water vapor transmission), chemical (release of drugs, hemostasis and/or adsorption of exudates and moisture) and biological (antimicrobial effects and improvement of healing) properties of wound dressings. In summary, inorganic ingredients have proved to be a promising and easily accessible products in the treatment of wounds and, more importantly, chronic wounds.

Incorporation of Brazilian Diatomite in the Synthesis of An MFI Zeolite.

The need for greener procedures is a fact to reduce residues, to decrease industrial costs, and to accomplish the environmental agreements. In an attempt to address this question, we propose the addition of a natural resource, Brazilian diatomite, to an MFI zeolite traditional synthesis. We have characterized the resulting product with different techniques, such as X-ray diffraction, microscopy, and gas sorption, and, afterwards, we evaluate the greenness of the process by the Green Star method. The results were promising: We obtained the desired topology in the form of small crystallites aggregated and a pore diameter of 0.8 nm. In conclusion, the product has the necessary characteristics for an adsorption or catalytic future tests and escalation to industrial production.