Eutectogel-Based Drug Delivery: An Innovative Approach for Atenolol Administration.

Hypertension affects 32% of adults worldwide, leading to a significant global consumption of cardiovascular medications. Atenolol, a β-adrenergic receptor blocker, is widely prescribed for cardiovascular diseases such as hypertension, angina pectoris, and myocardial infarction. According to the Biopharmaceutics Classification System (BCS), atenolol belongs to Class III, characterized by high solubility but low permeability. Currently, atenolol is commercially available in oral formulations. Increasing attention is being directed towards developing cost-effective transdermal delivery systems, due to their ease of use and better patient compliance. Eutectogels represent next-generation systems that are attracting great interest in the scientific community. Typically obtained from deep eutectic solvents (DESs) combined with gelling agents, these systems exhibit unique properties due to the intrinsic characteristics of DESs. In this study, a DES based on choline chloride as a hydrogen bond acceptor (HBA) and propylene glycol as a hydrogen bond donor (HBD) was explored to enhance the topical delivery of atenolol. The solubility of atenolol in the DES was evaluated using spectroscopic and thermodynamic measurements which confirmed the formation of hydrogen bonds between the drug and DES components. Additionally, the safety of the DES was assessed in a cell viability assay. Subsequently, we formulated eutectogels with different concentrations using animal gelatin and Tego Carbomer 140, and characterized these formulations through rheological measurements, swelling percentage, and permeation studies with Franz cells. These novel eutectogels exhibit superior performance over conventional hydrogels, with a release rate of approximately 86% and 51% for Carbomer- and gelatin-based eutectogels, respectively. In contrast, comparable hydrogels released only about 27% and 35%. These findings underscore the promising potential of eutectogels for the transdermal delivery of atenolol.