Self nanoemulsifying drug delivery systems of gemfibrozil were developed under Quality by Design approach for improvement of dissolution and oral absorption. Preliminary screening was performed to select proper components combination. Box-Behnken experimental design was employed as statistical tool to optimize the formulation variables, X1 (Cremophor® EL), X2 (Capmul® MCM -C8), and X3 (lemon essential oil). Systems were assessed for visual characteristics (emulsification efficacy), turbidity, droplet size, polydispersity index and drug release. Different pH media were also assayed for optimization. Following optimization, the values of formulation components (X1, X2, and X3) were 32. 43%, 29.73% and 21.62 %, respectively (16.22% of gemfibrozil). Transmission electron microscopy demonstrated spherical droplet morphology. SNEEDS release study was compared to commercial tablets. Optimized SNEDDS formulation of gemfibrozil showed a significant increase in dissolution rate compared to conventional tablets. Both formulations followed Weibull mathematical model release with a significant difference in td parameter in favour of the SNEDDS. Equally amodelistic parameters were calculated being the dissolution efficiency significantly higher for SNEDDS, confirming that the developed SNEDDS formulation was superior to commercial formulation with respect to in vitro dissolution profile. This paper provides an overview of the SNEDDS of the gemfibrozil as a promising alternative to improve oral absorption. She is an expert in nanotechnology (colloids and nanoparticles) with a wide experience. She has extensive curriculum of published paper about this subject Jose Luis Arias Mediano Ph. D. Professor reseracher, Pharmacy and Pharmaceutical Technology , University of Granada jlarias@ugr.es He is an expert in nanotechnology (colloids and nanoparticles) with a wide experience in this type of investigation. Also is reviewer in specialized pharmaceutical journal. He is an expert in nanotechnology (colloids and nanoparticles) with a wide experience in this type of investigation. Also is reviewer of Pharmaceutical science journals. IJP AUTHOR CHECKLISTDear Author, It frequently happens that on receipt of an article for publication, we find that certain elements of the manuscript, or related information, is missing. This is regrettable of course since it means there will be a delay in processing the article while we obtain the missing details.In order to avoid such delays in the publication of your article, if accepted, could you please run through the list of items below and make sure you have completed the items. Overall Manuscript Electronic artwork format? ---------------------------------------------------TIFF

HIGHLIGHTSA spectrofluorometric method has been developed for the determination of gemfibrozil.The method is based on the excitation and emission capacities of gemfibrozil.This method allows de determination of the drug in SNEDDS.Results showed linear relationships, low limits of LOD and LOQ with good robustness. GRAPHICAL ABSTRACTValidated spectofluorometric method for determination of gemfibrozil in self nanoemulsifying drug delivery systems (SNEDDS) Article history: ABSTRACT A spectrofluorometric method has been developed and validated for the determination of gemfibrozil. The method is based on the excitation and emission capacities of gemfibrozil with excitation and emission wavelengths of 276 and 304 nm respectively. This method allows de determination of the drug in a selfnanoemulsifying drug delivery system (SNEDDS) for improve its intestinal absorption. Results obtained showed linear relationships with good correlation coefficients (r 2 > 0.999) and low limits of detection and quantification (LOD of 0.075 μg mL −1 and LOQ of 0.226 μg mL −1 ) in the range of 0.2-5 μg mL −1 , equally this method showed a good robustness and stability. Thus the amounts of gemfibrozil released from SNEDDS contained in gastro resistant hard gelatine capsules were analysed, and release studies could be performed satisfactorily.