Burow’s solution is a 13% aluminum acetate solution used for treating chronic suppurative otitis media. However, multiple formulations for Burow’s and neo-Burow’s solutions are used as in-hospital preparations. Each formulation uses different types and amounts of reagents, and takes a different time to prepare. Thus, the ions, including aluminum ion (Al³⁺), and other molecules in the prepared Burow’s and neo-Burow’s solutions are not identical, and the pH also differs. Furthermore, details about the antibacterial activity of these preparations are unknown. This study evaluated the stability and antibacterial activity of four Burow’s and two neo-Burow’s solutions prepared using different methods. Preparation times ranged from 20 min to 3 d, and the pH ranged from 2.2 to 4, meaning some solutions were more acidic or more basic than the pH 3 devised by Burow. In addition, the Al³⁺ concentrations ranged from 0.05 to 1.51 mol/L, meaning some solutions were more concentrated or diluted than 13% aluminum acetate (0.64 mol/L). One of the Burow’s solutions we prepared produced a white residue after 14 d, making it difficult to ensure stability. In addition, confirming the antibacterial activity of another Burow’s solution against the test bacteria was problematic. Despite the differences in pH and Al³⁺ concentrations between the various Burow’s and neo-Burow’s solutions, the antibacterial activity was equivalent. It was considered necessary to use the basic data obtained in this study to select a formulation for each hospital. Evaluation of the antibacterial activity of each formulation in clinical settings will be a subject for future study.