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Absorption characteristics of once-a-day slow-release theophylline preparation in children with asthma
Insights
This study investigated a new sustained-release theophylline (SRT) formulation for once-daily dosing in children. SRT demonstrated consistent absorption and complete bioavailability, suitable for many pediatric patients.
Area of Science:
- Pharmacokinetics
- Pediatric Pharmacology
- Drug Formulation
Background:
- Theophylline is a bronchodilator used for respiratory conditions.
- Sustained-release formulations aim to improve patient compliance and reduce dosing frequency.
- Evaluating new drug delivery systems in pediatric populations is crucial.
Purpose of the Study:
- To assess the single- and multiple-dose absorption characteristics of a novel sustained-release theophylline preparation in children.
- To determine the suitability of this formulation for once-daily dosing in pediatric patients aged 8 to 14 years.
Main Methods:
- Four single doses of the sustained-release theophylline preparation were administered one week apart.
- During steady-state, the preparation was given once daily for one week, with serum theophylline concentrations monitored over 48 hours.
- The impact of meals on absorption was evaluated.
Main Results:
- The formulation exhibited excellent sustained-release properties and consistent absorption, unaffected by meals.
- Complete bioavailability was observed after both single and multiple doses.
- Most children (8/14) showed steady-state serum theophylline fluctuations below 90% with once-daily dosing.
- Day-to-day variations in serum theophylline levels were minimal in most patients.
Conclusions:
- The sustained-release theophylline formulation is completely absorbed at a slow, consistent rate, allowing for acceptable fluctuations with once-daily dosing in many pediatric patients.
- The formulation's suitability for very young children requires further investigation.
- This new preparation shows promise for once-daily theophylline therapy in older children.
Abstract:
The single- and multiple-dose absorption characteristics of a new sustained-release theophylline preparation, which has been formulated for once per day dosing in adults, were investigated in children aged 8 to 14 years. Four single doses were studied, each dose separated by 1 week. During steady state the preparation was given once daily in the morning for 1 week, and serum theophylline concentration was determined through two dosing intervals (48 hours). The product showed excellent sustained-release characteristics and consistent absorption profiles, which were not affected to any clinically important extent by the intake of various meals. After single doses, only 77% to 91% of the product was absorbed during the first 28 hours after dosing. However, bioavailability was complete both after single doses and during steady state. Eight of 14 children had steady-state fluctuations in serum theophylline levels of less than 90% when given doses once daily. Steady-state day-to-day variations in serum theophylline profiles were small in all patients except one, in whom differences up to 33 mumol/L (6 micrograms/mL) were seen (8 hours after dosing). We conclude that this formulation is completely absorbed at a sufficiently slow and consistent rate to permit acceptable fluctuations in absorption with once daily dosing for many, but not all, patients. However, it should not be used in very young children until bioavailability has been studied in this age group.