  Citation: Gavan, A.; Colobatiu, L.; Hanganu, D.; Bogdan, C.; Olah, N.K.; Achim, M.; Mirel, S. Development and Evaluation of Hydrogel Wound Dressings Loaded with Herbal Extracts. Processes 2022, 10, 242. https://doi.org/10.3390/pr10020242 Academic Editor: Sara Liparoti Received: 15 December 2021 Accepted: 24 January 2022 Published: 26 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). processes Article Development and Evaluation of Hydrogel Wound Dressings Loaded with Herbal Extracts Alexandru Gavan 1 , Liora Colobatiu 1, *, Daniela Hanganu 1 , Catalina Bogdan 1 , Neli Kinga Olah 2,3 , Marcela Achim 1 and Simona Mirel 1 1 Faculty of Pharmacy, Iuliu Hatieganu University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; gavan.alexandru@umfcluj.ro (A.G.); dhanganu@umfcluj.ro (D.H.); catalina.bogdan@umfcluj.ro (C.B.); machim@umfcluj.ro (M.A.); smirel@umfcluj.ro (S.M.) 2 Faculty of Pharmacy, Vasile Goldis Western University of Arad, 310025 Arad, Romania; neli.olah@plantextrakt.ro 3 PlantExtrakt Ltd., Radaia, 407059 Cluj, Romania * Correspondence: mihaiu.mihaela@umfcluj.ro Abstract: The current study aimed to develop carbomer based hydrogel dressings, incorporating ethanolic extracts of Rosmarinus officinalis aerial parts, Achillea millefolium and Calendula officinalis flowers. The pharmaceutical properties of the obtained hydrogels, as well as their texture and antimicrobial activity, were further evaluated. Five wound dressing formulations based on carbopol were prepared. The addition of the ethanolic extracts to the formulation slightly lowered the pH of the hydrogels, as expected. The Rosmarinus officinalis aerial parts extract loaded hydrogel proved to be the firmest one. In terms of consistency and viscosity, the behavior of the five hydrogels was relatively similar. Based on the texture analysis, the texture of the hydrogels has been affected to some extent by the addition of the ethanolic extracts, decreasing their consistency, firmness, and adhesiveness. The hydrogel loaded with Rosmarinus officinalis aerial parts extract and the one incorporating the blend of extracts (mixture of the three above-mentioned extracts) proved to have a good antimicrobial activity. The studied hydrogel formulations could serve as a basis for the development of novel wound dressing materials, although more extended in vivo studies would be needed in order to support current results. Keywords: wound dressing; herbal extract; carbomer gel; texture analysis; antimicrobial activity 1. Introduction Hydrogels are among the most used dressing materials that have confirmed their effectiveness in wet wound therapy. The three-dimensional polymer networks formed in hydrogels have the capacity to incorporate large quantities of water, ensuring not only the humid environment necessary for wound healing, but also an excellent biocompatibility [1]. The water retaining properties of the hydrogel dressings are induced by the presence of hydrophilic groups in the polymer chains, with the higher water content assuring a porous, soft, and elastic structure, thus enhancing the compatibility with biological tissues [2]. Hydrogels are obtained from natural polymers, such as cellulose, alginate, chitosan, gelatin, dextran, or from synthetic ones, like polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or polyethylene glycol (PEG). Their physicochemical properties—which influence the clinical behavior of the dressing—depend on the chemical nature of the monomer (natural or synthetic), on the structure of the polymer chain (the resistance of the covalent bonds and intermolecular forces), and molecular weight, but also on the synthesis method of the polymer [3,4]. Hydrogel wound dressings are recommended for their healing promoting properties, accelerating the process of granulation and epithelialization, being recognized as a first aid Processes 2022, 10, 242. https://doi.org/10.3390/pr10020242 https://www.mdpi.com/journal/processes