Formulation of Ibuprofen Beads by Ionotropic Gelation

Microencapsulation has become a common technique in the production of controlled release dosage forms. Many results have been reported, concerning the use of alginate beads as controlled release drug formulations. Alginate has a unique gel-forming property in the presence of multivalent cations, in an aqueous medium. Ibuprofen is an excellent analgesic and antipyretic, non-steroidal anti-inflammatory agent with a high therapeutic index. Formulation of ibuprofen in beads could reduce its gastric ulcerogenicity. Hence, in this study the formation of Ca-alginate ibuprofen beads, through ionotropic gelation has been investigated.

For this purpose, different cross- linking agents including: Ca²⁺, Ba²⁺, Mn²⁺, Co²⁺, Sn²⁺ and Pb²⁺, were used for bead preparation. Next, characterization of the beads, size distribution, encapsulation efficiency of ibuprofen within the beads, the bead swelling and the drug release kinetic were investigated.

Results showed that only Ca ion is suitable for the formation of ibuprofen beads. A good swelling profile for beads in phosphate buffer (pH=7.4) and the lack of swelling in hydrochloric acid (pH= 1.2), show the suitable nature of the beads. In addition, formulation of Na-alginate (2%) and Ca-chloride (2%) beads,resulted in an encapsulation efficacy of around 90%. The drug release studies showed a rapid and complete ibuprofen release from the beads, specially those prepared from Na-alginate (2%) and Ca-chloride (2%), in phosphate buffer medium.However, no detectable drug release was observed within the acidic medium.

In conclusion, ibuprofen is capable of being n be microencapsulated as a bead formulation, with suitable properties and release profile.