Entrapment of Ibuprofen by Multilamellar Liposomes for Aerosol Drug Delivery Towards Sustained Release Upon Pulmonary Administration

Author(s): Ange Imanishimwe, Adam Taylor, Manal Almalki, and Edward P.C. Lai

Purpose: Ibuprofen, a drug commonly used for treatment of inflammation and pain, has a short half-life which requires that the patient takes multiple doses a day to see a lasting effect in the cardiovascular system. Multilamellar liposomes (MLLs) have previously been shown to be effective nanocarriers in prolonging the administration cycle of similar drugs. The aim of this research is to entrap ibuprofen in MLLs and to evaluate these ibuprofen-loaded MLLs for sustained drug release during pulmonary delivery.

Methods: MLLs were prepared by the lipid hydration method wherein a thin film of ibuprofen and lecithin was heated past the critical temperature for efficient hydration. Stability test of the MLLs entrapping ibuprofen was confirmed by an incubation test at room temperature over 24 hours. To simulate physiological conditions expected in the lung, a surfactant (tween 20) was added to test the stability of the ibuprofen-entrapped MLLs. Then, any release of ibuprofen from the MLLs was determined by capillary electrophoretic analysis.

Results: Ibuprofen was successfully loaded into the MLLs with a diameter of 892-1713 nm at a high efficiency of 92%. There was no release of ibuprofen from the MLLs during the stability test under incubation at room temperature over 24 hours. However, sustained release of ibuprofen from the loaded MLLs at a rate of 0.09 mg/mL/hour was observed under physiological conditions expected in the lungs.

Conclusions: Our results suggest that MLLs could protect ibuprofen during administration in a pulmonary delivery system. Drying in a phosphate-buffered saline preserved the integrity of MLLs for long-haul transportation as well as long-term storage.