Formulation of controlled-release products

Area of Science:

• Pharmacology
• Drug Delivery Systems

Background:

• Numerous prolonged-release theophylline products exist, each with unique claims.
• The field of controlled drug delivery has a long history but is still developing a strong theoretical and clinical foundation.

Purpose of the Study:

• To provide an overview of controlled drug delivery.
• To discuss the characteristics of available sustained- or controlled-release theophylline products.

Main Methods:

• Review of theoretical principles in controlled drug delivery.
• Analysis of biologic constraints for oral administration.
• Overview of current sustained- and controlled-release product types.

Main Results:

• Many sustained-release products are developed empirically.
• Clinical testing in healthy volunteers may not reflect real-world performance.
• Controlled drug delivery is an emerging discipline with a growing theoretical and clinical base.

Conclusions:

• The development of sustained-release theophylline products often relies on empirical methods.
• There is a need for improved clinical relevance in the testing of these drug delivery systems.
• Controlled drug delivery is advancing as a scientifically-grounded field.