LAUSR

Two automatic methodologies were developed to perform the loading and release assays of drugs from porous silicon (PSi) nanoparticles. 5-Fluorouracil (5-FU) was selected as a model drug, and different functionalized PSi nanoparticles were used. While for drug loading studies the reproducible characteristics of flow systems were explored regarding mixture and volumes taken, in the drug release flow methodology versatility in accommodating different devices around the valve were tested. Fluorescent properties of 5-FU were used with detection limit of 9 × 10-4 mg L-1 and a linear response up to 5 mg L-1 The drug loading and release procedures were optimized in sequential injection analysis (SIA) systems obtaining a huge economy regarding the time spent (4 min towards 2 h). Batch and SIA methods were tested and compared for the different behaviours of the PSi nanoparticles towards both methodologies and no noteworthy differences were obtained with Student's t-test for loading with a calculated t value of 2.04 showing the absence of statistical differences. All the results present a RSD less than 10%. So, the developed automatic methodologies are a viable alternative to load drugs and to study the release profiles from PSi nanoparticles.