## 1 Introduction  
Skin diseases are a significant problem affecting people worldwide [1]. In these diseases, there are various skin lesions within individual layers of the skin, often accompanied by persistent itching, burning of the skin, and soreness [2]. Due to many limitations of currently available therapies, new solutions are still being sought, including new carriers of active substances that could help rise to this challenge. Treatments involving the topical application of medicinal substances are being developed globally due to the multiple systemic adverse effects of oral therapies that are routinely used to treat skin problems [3]. Numerous attempts have been made to develop various drug carriers that would enable increased penetration of biologically active substances into the skin, contributing to the surface effect of medicinal substances and improving transdermal therapy [4]. Hydrogels are promising carriers of natural compounds that can significantly improve the treatment effectiveness of skin diseases. These drug delivery systems (DDSs) are three-dimensional polymer networks into which many therapeutic compounds, both hydrophilic and hydrophobic, can be incorporated, which allows them to be used in the treatment of a wide range of diseases [5; 6]. The ability to design smart hydrogels that can release embedded substances in a controlled manner in response to changing stimuli allows for control of the release rate of therapeutic compounds from these three-dimensional networks [7]. Therefore, hydrogel carriers are one of the most dynamically developing groups of medical materials, and their use in cosmetology and dermatology is constantly increasing. Their remarkable advantage is the ease of application and significant minimization of side effects associated with the topical method of drug application, leading to therapeutic concentrations in individual layers of the skin without increasing the concentration in the serum [8]. Hydrogels based on natural polymers, characterized by high biocompatibility, biodegradability, and low toxicity and immunogenicity, are currently gaining great popularity [9]. Their physical properties are similar to natural tissues, and the constant development of various chemical and physical strategies for their synthesis led to obtaining biofunctional hydrogels with the desired properties in treating specific skin diseases [10]. The use of hydrogels in the treatment of various dermatological diseases and in improving the condition of the skin focuses primarily on their use as carriers with a highly controlled release of active substances in treating local skin lesions, in tissue engineering, regenerative medicine, and cell therapy [6; 11; 12]. The enormous potential of active, natural-origin substances used to treat many skin diseases has been described in scientific reports for a long time. Natural compounds assessed in the context of their therapeutic application in the treating of skin diseases are analyzed primarily in terms of their antioxidant, anti-inflammatory, and antimicrobial activity [13]. In order to assess the safety of their use, cytotoxicity and genotoxicity tests are also carried out [14]. A promising compound in treating various skin diseases is cannabidiol (CBD), which has a comprehensive therapeutic effect [15]. Because the endocannabinoid system is a fundamental molecular system responsible for controlling and maintaining homeostasis in the body, it is nowadays a common target of pharmacotherapy [16]. After discovering the endocannabinoid system of the skin and its essential role in maintaining the homeostasis of this organ, interest in phytocannabinoids increased significantly [17]. CBD, by interacting with cannabinoid receptors and other elements of the endocannabinoid system, may contribute to achieving satisfactory treatment effects related to its multidirectional action [16].