Effect of manufacturing method on the in vitro drug release and adhesive performance of drug-in-Adhesive films containing binary mixtures of ibuprofen with poloxamer 188

Drug-in-adhesive acrylic films, containing binary mixtures of ibuprofen:poloxamer 188 in 30:70, 40:60, 50:50, and 60:40 ratios, were prepared by incorporation either as physical mixture (PM), molten mixture (MM), or solid dispersion (SD). Dissolution testing showed that films prepared by MM had higher drug release compared to films prepared by PM, SD, and films containing ibuprofen alone. The MM 50:50 ratio showed the highest drug release (p<0.05). Examination of the films by differential scanning calorimetry showed melting endotherms from the binary crystalline mixture but not from ibuprofen crystals regardless of the preparation method. Rheological measurements showed that MM films had lower elastic moduli compared to the neat adhesive, due to the plasticizing effect of the dissolved binary mixture. Fourier transfer infrared analysis confirmed the absence of ibuprofen crystal dimers in all films. It was therefore concluded that the MM method provided better mixing of the components providing crystal-free supersaturated films of high thermodynamic activity.