Stability of anhydrous theophylline in extemporaneously prepared alcohol-free oral suspensions

Abstract

In 2001, theophylline was the number one medication prescribed worldwide for the treatment of asthma.1 Despite this, the use of theophylline in the United States has declined drastically in the past decade. In addition, the focus of maintenance asthma treatment has shifted from bronchodilation to primary control of airway inflammation. This switch has emphasized the use of inhaled corticosteroids and left theophylline with a greatly diminished role in the treatment of chronic asthma in the United States.1 Inhaled corticosteroids are expensive, and their long-term effects are not yet known. Studies have shown that theophylline, in combination with inhaled corticosteroids, can significantly improve lung function with respect to forced expiratory volume.2,3 Furthermore, it has been suggested that theophylline may enhance the antiinflammatory effects of corticosteroids, reducing the steroid resistance often observed in patients with chronic obstructive pulmonary disease and severe asthma in whom corticosteroid use alone was ineffective.2 Theophylline is also used to treat other obstructive airway diseases, such as cystic fibrosis. In cystic fibrosis, theophylline is beneficial because it enhances mucociliary clearance, reduces bronchoconstriction, and decreases respiratory muscle dysfunction.4