Characterization of Solid SNEDDS
As the final dosage form of the solid SNEDDS is a tablet or a capsule, the powder properties of the solid emulsion particles are important. The nature and the quantity of liquid SNEDDS adsorbed on the surface of a particular excipient would influence the properties of the obtained solid particles. The ratio of liquid:adsorbent quantity is important. Powder properties, such as density, angle of repose, flow, compressibility index and particle size distribution, are important for processing into dosage form. The globule size of spontaneously formed nanoemulsion would govern its performance in vivo. The desorption of SNEDDS from the surface of the solid particles and its conversion into nanoemulsion is the rate-limiting step for the dissolution and absorption of the drug. In our study, an increase in the globule size of the nanoemulsions was observed when the solid nanoemulsifying particles were dispersed in water. Increase in size was not only related to the carrier used but also to the composition of SNEDDS and properties of the drug.[53] It is necessary to carry out physical characterization of the solid SNEDDS using x-ray diffraction spectroscopy, differential scanning calorimetry and scanning electron microscopy to ensure there is no drug precipitation during preparation of solid SNEDDS. The absence of characteristic drug melting endotherm in differential scanning calorimetry suggests that the drug is in a solubilized state in solid SNEDDS. X-ray diffraction is a useful technique employed in the characterization of crystalline materials. The formation of a diffuse diffraction pattern and the disappearance of characteristic drug peaks indicate that the drug is in a solubilized state in solid SNEDDS. Scanning electron microscopy is useful to investigate the surface properties of the particles and their physical form. In vitro dissolution studies would give an idea about the fate of the formulation in the GI tract.
Nanomedicine. 2010;5(10) © 2010 Future Medicine Ltd.
Cite this: Self-nanoemulsifying Drug Delivery Systems: Formulation Insights, Applications and Advances - Medscape - Dec 01, 2010.
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