Plasma theophylline concentrations following the oral administration of microcrystalline theophylline and a new sustained-release theophylline preparation to normal subjects

Sustained-Release Theophylline Preparations

“…The relative therapeutic availabil ity of the three preparations studied as the mean of data from smokers and non-smok ers was Theograd 80%, Theolair Retard 96%, and Theolin Retard 101%. These val ues correlate well with those in the litera ture [11][12][13][28][29][30]32].…”

“…Most single-dosing and multiple-dos ing studies of theophylline are conducted on small numbers of patients or on heal thy volunteers [7][8][9][10][11][12][13]. Patients are usually hospitalised in-patients [14][15][16], and both the patients or volunteers selected, as well as the conditions of the study, are careful ly controlled.…”

Plasma theophylline concentrations in patients with chronic obstructive airways disease after administration of a new sustained release theophylline formulation.

“…The natural fluctuation of airway obstruction, combined with the relatively short half-life of theophylline and its potentially serious adverse effects at concentrations greater than 20 ,ug/ml, have resulted in the development of a number of slow release theophylline preparations in the hope that optimum therapeutic effect would be obtained for a sustained period with minimum risk of toxicity. One of these sustained release tablets of theophylline (Nuelin SA, Riker Laboratories) has been shown to have adequate dissolution and absorption properties and to achieve satisfactory plasma theophylline levels in normal subjects (Russell et al, 1980). The purpose of this study was to examine its effects in patients with chronic obstructive airways disease.…”

Delay in the absorption rate of theophylline from a sustained release theophylline preparation caused by food.

“…Studies with the sustained release theophylline preparation Nuelin Retard (Riker) have shown that peak serum levels of theophylline usually occur about 4 h after tablet administration in fasting patients (Russell et al, 1980;Svedmyr, Mellstrand & Svedmyr, 1979). However, most patients do not fast for some time after taking their tablets so it is important to know if the rate of absorption of sustained release theophylline (SRT) preparations is affected by the intake of food.…”