Assessment of Once Daily Controlled-release Ibuprofen Matrix Tablets Prepared using Eudragit ^®E100/Carbopol^® 971P NF Polymers and their Salt Combinations

Introduction: Hydrophilic polymers that swell or dissolve in aqueous media can have the potential to prepare controlled/sustained dosage forms for weakly acidic and poorly soluble drugs. Objective: The main objective of this study is to utilize Eudragit^®E100 (EE) and Carbopol^®971P NF (Cp) polymers and their salt forms for the preparation of a once-daily controlled-release matrix tablet for model drug, Ibuprofen (IB). Methods: Combinations of the polymers in their base forms (EE)/(Cp) or in their salt forms (EEHCl/ CpNa) were compressed with (IB) into single layer matrix tablets, or otherwise into bilayer tablets. Dissolution profiles were constructed using three different consecutive stages (pH 1.2, 4.8 and 6.8). Results: It was found that the incorporation of (EEHCl) modified the release rates of (IB) from (Cp) based matrix tablets. However, a major enhancement of (IB) release rates occurred when the polymers were combined in their salt forms in a 1:1 ratio by weight. In addition, a bilayer tablet was prepared wherein a relatively rapidly disintegrating layer composed of polymers salts (EEHCl and CpNa), and a second layer containing only (Cp) polymer in its base form in a 1:2 weight ratio possessed excellent release properties and mechanical strength. Conclusion: It was concluded that the prepared bilayer tablet could be promising for controlling the release rates of (IB) in an extended manner to allow once-daily administration with an improved pH-independent release behavior.