Lignosulfonate Microcapsules for Delivery and Controlled Release of Thymol and Derivatives.

Claudio Piombino,Heiko Lange,Claudia Crestini,Valeria Conte,Federica Sabuzi,Pierluca Galloni

doi:10.3390/molecules25040866

Abstract

Thymol and the corresponding brominated derivatives constitute important biological active molecules as antibacterial, antioxidant, antifungal, and antiparasitic agents. However, their application is often limited, because their pronounced fragrance, their poor solubility in water, and their high volatility. The encapsulation of different thymol derivatives into biocompatible lignin-microcapsules is presented as a synergy-delivering remedy. The adoption of lignosulfonate as an encapsulating material possessing relevant antioxidant activity, as well as general biocompatibility allows for the development of new materials that are suitable for the application in various fields, especially cosmesis. To this purpose, lignin microcapsules containing thymol, 4-bromothymol, 2,4-dibromothymol, and the corresponding O-methylated derivatives have been efficiently prepared through a sustainable ultrasonication procedure. Actives could be efficiently encapsulated with efficiencies of up to 50%. To evaluate the applicability of such systems for topical purposes, controlled release experiments have been performed in acetate buffer at pH 5.4, to simulate skin pH: all of the capsules show a slow release of actives, which is strongly determined by their inherent lipophilicity.

Highlights

The increasing number of antibiotic resistant pathogens has prompted the development of improved and innovative systems with antibacterial properties, without toxic effects on human cells [1].In recent years, research in the biopharmaceutical sector has especially focused on the combination of natural-derived elements, aiming at the development of biocompatible controlled-release systems.Controlled drug delivery and release offers numerous therapeutic benefits in terms of pharmacokinetics and pharmacodynamics, while avoiding formulation problems that are usually linked to the hydrophobicity of many active ingredients [2]
The synthesized substrates could be successfully incorporated into lignosulfonate-based microcapsules, while using sonication procedures
The encapsulation efficiencies have been measured for each system

Summary

Introduction

The increasing number of antibiotic resistant pathogens has prompted the development of improved and innovative systems with antibacterial properties, without toxic effects on human cells [1].In recent years, research in the biopharmaceutical sector has especially focused on the combination of natural-derived elements, aiming at the development of biocompatible controlled-release systems.Controlled drug delivery and release offers numerous therapeutic benefits in terms of pharmacokinetics and pharmacodynamics, while avoiding formulation problems that are usually linked to the hydrophobicity of many active ingredients [2]. The biocompatibility of the drug vehicle is pivotal [3,4] In this scenario, entrapment, in various forms of actives in matrices made of natural polymers, represents an interesting approach; numerous efforts have been published in this direction, using practically every type of natural polymer physically and chemically suitable [5]. Entrapment, in various forms of actives in matrices made of natural polymers, represents an interesting approach; numerous efforts have been published in this direction, using practically every type of natural polymer physically and chemically suitable [5] Lignin, in this respect, possesses key features to be part of this gathering, as has been recently summarized [6]

Methods

Results

Conclusion