Lipase Is Essential for the Study of <i>in Vitro</i> Release Kinetics from Organogels

<i>In vitro</i> drug release studies remain indispensable in the development of drug delivery systems, even if correlations between <i>in vitro</i> and <i>in vivo</i> results are often imperfect. In this work, an improved <i>in vitro</i> analysis method for studying <i>in situ</i>-forming lipid-based implants was developed. More specifically, lipase was found to be an essential additive for evidencing differences in drug release kinetics from organogels of different amino acid-based organogelators, organogelator concentrations, drug loadings, and volumes. Lipases are thought to participate in the degradation of and release from amino acid-based organogel implants <i>in vivo</i>. Our experimental conditions allowed for the rapid and reliable screening of <i>in vitro</i> parameters that may be optimized to slow or accelerate drug release, once preliminary <i>in vivo</i> data are available.