Introduction Drug Classification Pharmacology and medicine use the chemical properties of various natural and artificially created drugs for their treatment and development purposes. The focus of this report is the consideration of only the chemical properties of the drugs including metaproterenol sulfate, dyphylline, prednisolone, albuterol, salmeterol xinafoate, and theophylline. Metaproterenol sulfate is the generic name for corticosteroid MDI belonging to the class of rescue/reliever drugs. Dyphylline, also known as dihydroxypropyl theophylline, is rescue/reliever, it belongs to the class of “N-7 dihydroxypropyl derivative of theophylline” (Foye et al., 2007, p. 1245). Prednisolone belongs to the class of ∆-corticosteroids that display the features of anitrheumatic and antiallergenic agents and is 1-dehydro derivative of cortisone and hydrocortisone; it is rescue/reliever (Foye et al., 2007, p. 890). Next, albuterol is rescue/reliever and the drug belonging to the class of non-catechol selective β-agonists acting as the corticosteroid MDI and bronchodilator, while salmeterol xinafoate is the corticosteroid MDI and the long acting β-agonist belonging to the controller/preventer class of drugs. Finally, theophylline is also rescue/reliever drug belonging to the dimethylxanthine group (Foye et al., 2007, pp. 405; 406; 484). Therapeutic Use According to Foye et al. (2007) and Hernandez (2006), all the above mentioned drugs are used in pharmacology and therapy. Metaproterenol sulfate, dyphylline, prednisolone, albuterol, salmeterol xinafoate, and theophylline are bronchodilators serving as either rescue/relievers or controller/preventers in treating respiratory illnesses, and especially asthma (Foye et al., 2007, p. 1230; Hernandez, 2006, p. 205). The bulk of the drugs are administered via inhalation, while metaproterenol sulfate can also be administered orally in the form of tablets or pills. Molecular Properties of Selected Drugs Physical-Chemical Characteristics Acid-Base Characteristics The acid-base characteristics of the selected drugs demonstrate their composition of both strong and weak acids and only neutral bases. Metaproterenol sulfate consists of strong acids, H 2 SO 4 and CH 3 , and neutral bases OH; dyphylline, albuterol, theophylline, and prednisolone consist of a weak acid CH 2 OH and similar OH bases. The composition of salmeterol xinafoate presents neutral bases OH only (Foye et al., 2007, p. 28; Hernandez, 2006, p. 37). Accordingly, the pKa values of the weak acids range from -2 to 12, while strong acids in the selected drugs have pKa values less than -2. In acid-base reactions, the pKa are the values that allow figuring out the pKb values, i. e. the base dissociation constant according to the formular ~14 – pKa. Thus, in metaproterenol sulfate, the pKa of H 2 SO 4 is -3, so the pKb is ~14 – (-3) = 17. In prednisolone, the weak acid CH 2 OH has the pKa of 11.4, and the pKb is ~14 – 11.4 = 2.6. Overall Polarity and Its Effect on Solvation (Hydration), Solubility, Dissolution, Partitioning between Phases The selected drugs are characaterized by domination of polar molecules. Metaproterenol sulfate’s non-polar molecules include only carbon compounds like C