A single-dose comparison of four slow-release theophylline preparations in normal subjects

Abstract

SummaryThe plasma theophylline concentrations produced by 4 different slow release formulations, Theograd, Theodur, Theolair-SR and Rona-slophylline were measured over a 24-hr period in 8 healthy subjects. All 4 preparations maintained plasma levels over 12 hr and had similar AUC values when the difference in theophylline content was taken into account. Paired saliva and plasma theophylline concentrations gave a ratio of 1: 038, saliva: plasma, but with a large inter and intra individual variation.

Reproducibility of saliva and plasma theophylline levels following single dose administration of two sustained release preparations.

“…This study confirms the work of others (Boobis et al, 1979;Munch et al, 1981;Sharma et al, 1981) Saliva theophylline (pg ml1) Figure 2 The relationship between plasma and saliva theophylline levels for three subjects (A, B and C) each studied on three occasions. Correlation coefficients have been calculated where the relationship appeared linear.…”

“…Galant et al, 1977;Goldsworthy et al, 1981;Jonkman et al, 1981; Koysooko et al, 1974) have indicated a favourable correlation between the two, whilst others suggest that saliva is of little value (e.g. Boobis etal., 1979;Munch etal., 1981;Sharma et al, 1981). Some of the controversy might be explained by individual variability and our study was designed to investigate this in more detail.…”

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].…”

The Comparative Bioavailability of Slow Release Oral Theophylline Preparations

“…Sharma et ul. (9) simrlarly found the t-for Theolair-SR (identical to Nuelin-SA) to be 5.2 h and Rona-Slophyllin, 5.6 h. In contrast, the tmax value for Theodur has been reported to be relatively longer at 9 . 2 h and 7.1 h (8,9).…”

“…(9) simrlarly found the t-for Theolair-SR (identical to Nuelin-SA) to be 5.2 h and Rona-Slophyllin, 5.6 h. In contrast, the tmax value for Theodur has been reported to be relatively longer at 9 . 2 h and 7.1 h (8,9). This variability in reported t,, values may be explained not only by product variation but by the timing of food ingestion relative to drug administration.…”