Chitosan-magnesium aluminum silicate nanocomposite microspheres coated with poly(vinyl acetate phthalate) for controlled release of capecitabine

Design and Optimization of pH‐Responsive Chitosan‐Coated Zn‐Carboxymethyl Cellulose Hydrogel Bead Carriers for Amoxicillin Trihydrate Delivery

“…Therefore, this resulted in a faster release. The n values are higher because of the formation of a rigid polymer structure for the beads [7a] . While k values increased with increasing drug/polymer ratio, they decreased with increasing ZnCl 2 concentration.…”

“…In a previous study, [1b] flurbiprofen‐loaded chitosan‐coated NaCMC/PVA microspheres were produced by cross‐linking with Fe 3+ ions using the water‐in‐oil emulsion cross‐linking technique, and it was observed that CS coating significantly reduced flurbiprofen release. Angadi et al [7a] . produced composite microbeads of sodium alginate and sodium carboxymethyl cellulose containing magnesium aluminum silicate by enteric coating with chitosan and investigated the controlled release of amoxicillin from these beads in the stomach environment.…”

“…To investigate the presence of AMX in CS‐coated AMX‐loaded bead carriers, the spectra of AMX, CS‐coated empty bead carriers, and CS‐coated AMX‐loaded bead carriers were compared (Figure 3). The most important characteristic peaks in the FTIR spectrum of AMX are listed as follows: CN band NH stretching combination band at 1485 cm −1 , the C=C stretching (benzene ring) at 1520 cm −1 , the C=O stretching (amide I) at 1680 cm −1 , the C=O stretching (β‐lactam ring) at 1770 cm −1 , the amide NH and OH stretching (phenol) at 3440 cm −1 , and CH stretching (benzene ring) at 3020 cm −1 [7a,18] . Comparing the spectrum of CS‐coated AMX‐loaded bead carriers with the spectrum of CS‐coated empty bead carriers, all characteristic bands of AMX are seen in the spectrum of drug‐loaded bead carriers, proof of successful encapsulation of AMX into bead carriers.…”

“…This is due to the formation of a chitosan shell, which allows more drug particles to be retained in the CMC gel matrix during microsphere preparation. This reduces the possibility of the drug leaching out of the polymer system [1b,7a,15] …”

“…DSC thermograms of CS‐coated AMX‐loaded bead carriers, CS‐coated empty bead carriers, uncoated empty bead carriers, and AMX are given in Figure 7. It can be said that the peak at 104 °C in the thermogram of AMX corresponds to the melting point [7a] . In the thermogram of CS‐coated AMX‐loaded bead carriers, a sharp and broad endothermic peak was seen at about 152 °C, and a very wide peak at 355 °C was observed owing to degradation of the polymer matrix.…”