Tetracycline is one of the most commonly used antibiotics in a wide range of antibacterial drugs. Self-association of drugs (e.g. antibiotics) causes problems, such as increasing toxicity and reducing penetration of drugs through cell membranes. In this study, the self-association process of tetracycline was investigated experimentally and theoretically in aqueous, ethanol, and salt solutions. Spectroscopy studies showed that the self-association process occurred in salt solution at lower concentrations of tetracycline in comparison with the other two solutions. However, the presence of ethanol led to a delay in the self-association process. The self-association constants of tetracycline were obtained by using experimental values. Moreover, the analysis of the number of clusters and solvent accessible surface area were carried out by molecular dynamics (MD) simulations. The MD results clarified that the tetracycline self-association process happened earlier in salt solution compared to the others through forming the larger clusters by the hydrophobic interactions, whereas the presence of ethanol caused a reduction in the self-association process and the cluster populations through weakening the hydrophobic interactions. Furthermore, the type of the involved interactions in the formation of the tetracycline clusters was investigated by RDG analysis. The obtained results revealed that van der Waals interactions possessed a fundamental influence on the formation of tetracycline clusters.

四环素是多种抗菌药物中最常用的抗生素之一。药物（例如抗生素）的自缔合会引起问题，例如增加毒性和减少药物通过细胞膜的渗透。在这项研究中，在水溶液，乙醇和盐溶液中，从理论和实验角度研究了四环素的自缔合过程。光谱研究表明，与其他两种溶液相比，四环素浓度较低的盐溶液中发生了自缔合过程。然而，乙醇的存在导致自缔合过程的延迟。通过使用实验值获得四环素的自缔合常数。此外，通过分子动力学（MD）模拟进行了簇数和溶剂可及表面积的分析。MD结果表明，盐溶液中的四环素自缔合过程比其他溶液早，是通过疏水相互作用形成更大的团簇而发生的，而乙醇的存在则导致自缔合过程的减少，而通过弱化而导致团簇的数量减少。疏水相互作用。此外，通过RDG分析研究了四环素簇形成中涉及的相互作用的类型。所得结果表明范德华相互作用对四环素簇的形成具有根本性的影响。MD结果表明，盐溶液中的四环素自缔合过程比其他溶液早，是通过疏水相互作用形成更大的团簇而发生的，而乙醇的存在则导致自缔合过程的减少，而通过弱化而导致团簇的数量减少。疏水相互作用。此外，通过RDG分析研究了四环素簇形成中涉及的相互作用的类型。所得结果表明范德华相互作用对四环素簇的形成具有根本性的影响。MD结果表明，盐溶液中的四环素自缔合过程比其他溶液早，是通过疏水相互作用形成更大的团簇而发生的，而乙醇的存在则导致自缔合过程的减少，而通过弱化而导致团簇的数量减少。疏水相互作用。此外，通过RDG分析研究了四环素簇形成中涉及的相互作用的类型。获得的结果表明范德华相互作用对四环素簇的形成具有根本性的影响。而乙醇的存在则通过减弱疏水相互作用而减少了自缔合过程和簇的数量。此外，通过RDG分析研究了四环素簇形成中涉及的相互作用的类型。获得的结果表明范德华相互作用对四环素簇的形成具有根本性的影响。而乙醇的存在则通过减弱疏水相互作用而减少了自缔合过程和簇的数量。此外，通过RDG分析研究了四环素簇形成中涉及的相互作用的类型。获得的结果表明范德华相互作用对四环素簇的形成具有根本性的影响。