70 Address all correspondence to Panagiota Eleni, peleni@central.ntua.gr Preparation, Quality Characterization, and Shelf-Life Evaluation of Facial Cosmetic Cream Enriched with Encapsulated Tea Tree Oil PANAGIOTA ELENI, KLEOPATRA KALOUTA, NIKOLAOS PANAGIOTOU, KATERINA VASSILATOU AND MAGADALINI KROKIDA School of Chemical Engineering, Laboratory of Process Analysis and Design, National Technical University of Athens, Athens, Greece (P.E., K.K., N.P., M.K.) Cosmetics Innovation Consultant, The NuCLab, Athens, Greece (K.V.) Accepted for publication January 14, 2022. Synopsis Because of their effectiveness against microorganisms, a recent trend in the cosmetics industry is the replacement of specific chemical compounds with safe natural substances. However, many of the natural extracts that could replace these chemical components present nondesirable sensory properties to final products that prevent their usage. This study aims to present and characterize cosmetic facial cream with acceptable sensory characteristics and shelf-life that contain encapsulated tea tree oil (TTO). For the encapsulation of TTO in β-cyclodextrin’s polymeric matrix, microfibers were applied during the electrohydrodynamic process and scanning electron microscopy images were analyzed to select the optimum conditions. The microfibers were then incorporated into a facial cosmetic cream. All samples were stored at three different temperatures and microbiological analysis for color and pH measurements were performed for all formulations. Microbial analysis reveal no microbial contamination at all storage temperatures. Moreover, the pH and color of the creams that contained TTO microfibers performed differently than the base cream, which was expected due to the TTO quantities released over time. In general, all of the formulated creams presented similar characteristics that were not affected by different storage conditions. The addition of encapsulated TTO in cosmetic creams could develop formulations suitable for use due to their microbiological aspects and quality characteristics. The electrohydrodynamic process could be the key to the formation of cosmeceutical products containing selected compounds regardless of their undesirable sensory characteristics or the thermosensitivity of the compounds. INTRODUCTION There is a recent trend toward replacing chemical compounds in cosmetic formulations following consumer requirement that natural compounds be incorporated into cosmetic products. Negligent use of synthetic components has been proven to provoke harmful consequences in consumer health and cause several skin issues, like irritations and allergies, with the most reported cases after use of facial cosmetic products (1). Irritant reactions are J. Cosmet. Sci., 73, 70–83 (March/April 2022)