Application of fatty acid-based eutectic mixture as a phase change material in microencapsulation of drugs: preparation, characterization and release behavior

Abstract

Recently, microencapsulation has developed in various industries with its versatile applications. Its profound impact is particularly notable in the chemical, food, and pharmaceutical sectors. Among its research areas, the microencapsulation of drugs using phase change materials (PCMs) stands out as a groundbreaking advancement in drug delivery systems. This innovative approach involves encasing drugs within a PCM shell, significantly enhancing their stability and delivery regulation. The focus of our study is the microencapsulation of certain drugs with poor water solubility namely, cyclosporine, baclofen, and biotin within a bio-based PCM. It has identified PCMs with phase transition temperatures near human body temperature ( 310 K) as ideal candidates for this purpose. A eutectic mixture of stearic-lauric acid in a 1:3 mole ratio was selected for its optimal phase change properties to create microcapsules with core–shell morphology in spherical form. Our comprehensive characterization of the microcapsules, validated by FT-IR and SEM techniques, confirms their proper formation. All studied drugs microencapsulated with the PCM exhibited an excellent thermal stability at working temperature from thermal stability analysis based on TGA results. Furthermore, differential scanning calorimetry (DSC) tests conducted on the microencapsulated drugs obtained the melting point of all three microencapsulated drugs near the melting point of PCM. Also, the release behavior of drugs from drug delivery method was investigated in PBS (pH 7.4) and two temperatures (310.15 and 318.15) K. Drug release occurred sustainably, such that 50% and about 60% of the total of each drug was released from the microcapsules at mentioned temperatures respectively during 24 h.