Chitosan-Coated Lipid-Bile Salt-Surfactant Hybrid Colloidal Micellar Nanocarrier with PH-Responsive Properties

A pH-responsive polymer-coated hybrid colloidal micellar nanocarrier was developed as a mixed lipid–polymer nanostructure for the delivery and controlled release of Diclofenac to mildly acidic environments (inflamed or tumor tissues). The particles, composed of lecithin, cholesterol, chitosan, sodium cholate, and sodium dodecyl sulfate, remain stable under normal physiological conditions. Synthesized via the thin-film hydration method, the nanocarriers were characterized using turbidimetric analysis, electron microscopy (SEM and TEM), spectrophotometry, HPLC, and capillary electrophoresis. SEM and TEM confirmed a spherical shape, with a diameter of 35–45 nm in the dehydrated state. The particles exhibited good stability, maintaining integrity for over two months at 4 °C and for several hours at 37 °C and 39 °C. The zeta potential was evaluated at −24.7 mV. Decreasing the pH from 7.42 to 6.0 triggered rapid degradation at the beginning of the process, followed by a slowdown throughout the observation period. Quantification showed pH-dependent diclofenac release. This hybrid micellar platform is a feasible stimuli-responsive nanosystem for controlled delivery and effective release of hydrophobic drugs.