ABSTRACT
INTRODUCTION: In recent decades, drug delivery applications have extensively utilized hydrogel systems based on natural polymers. Among the numerous biopolymer-based hydrogel drug delivery systems reported, a novel pectin-like substance was extracted from fig leaves and copolymerized with chitosan. METHOD: The hydrogel was reformed into microspheres using glutaraldehyde (chemical cross-linker) and sodium hexametaphosphate (physical cross-linker). The extracted polysaccharide and the prepared hydrogels were characterized by FTIR, GC/MS, SEC/MALS/DRI as well as XRD, SEM, BET, and thermal analysis. SEM images revealed the formation of porous microspheres with an average size of 50 µm in diameter. Degrees of swelling in pH7 at 35°C have shown the hydrogels reached two to three times their weights. This has been reflected in their ability to load drugs or any other chemicals. The loading formula shows that hydrogels have maximum loading efficiency more than one-third of the weight of hydrogel. The antimicrobial ciprofloxacin was used as a model for loading on prepared hydrogels. The loaded hydrogels were tested for their biological activities against staphylococcus aureus (S. aureus) bacteria. The antimicrobial growth inhibition zone of the cultured (S. aureus) by ciprofloxacin-loaded hydrogel was followed, which shows controlled growth in inhibition zone sizes and for long time intervals. Results showed that the pectin-chitosan hydrogels exhibited significant antibacterial activity against gram - positive bacteria (S. aureus), with an inhibition zone of 45 mm for (CH-co-FLP)/GLU hydrogel. RESULT: In vitro, the ciprofloxacin-loaded hydrogels were studied and the cumulative release of ciprofloxacin under suitable conditions was found in a controlled manner and kept release for a long time interval. Data exhibited that the cumulative release profile of ciprofloxacin from the hydrogel demonstrated sustained release over 48 hours, with a value of 6.9% released within the first 24 hours and 7.0 and 6.9% % released at the end of the study for the (CH-co-FLP)/GLU and (CH-co-FLP)/SMP hydrogels, respectively. CONCLUSION: The novel pectin-chitosan hydrogels hold the potential to enhance the quality of life for numerous patients by minimizing the need for frequent intake of chronic medications.
ABSTRACT
The cross-linked microspheres were prepared and loaded with Favipiravir SARS-CoV-2 antiviral drug, by copolymerization of chitosan (CS) with a polysaccharide extracted from fresh pomegranate peels. Moreover, glutaraldehyde (Glu) has been used as a chemical cross-linker and sodium hexametaphosphate (SHMP) as a physical cross-linker. The extracted polysaccharide was analyzed, and different techniques have been used. The analyses lead to the conclusion that it is pectin. The surface morphology of the prepared microspheres was studied using a scanning electron microscope, where the size and shape factor (S) of the Glu microspheres showed high values (74.27 µm) and (0.852), respectively, meaning their surfaces tend to be rough, whereas the SHMP microspheres showed a smaller size particle (20.47 µm) and a smaller shape factor (0.748), which gives an indication that the SHMP microspheres have smooth surfaces. The swelling studies have shown that Glu microspheres have a higher degree of swelling, which means SHMP microspheres are more compact. The prepared microspheres have shown a higher loading percentage of Favipiravir antiviral drug in SHMP microspheres (37% w/w) in comparison with Glu microspheres (35% w/w), where the electrostatic interaction between the Favipiravir ions and SHMP anions helps for more loading. The microspheres prepared under different types of cross-linking have shown initial burst release of Favipiravir, followed by a step of controlled release for a certain period of time, whose period depends on the pH of the release medium. Both Glu and SHMP cross-linked microspheres have shown high controlled release times in buffered release solutions at pH = 7.4 and for shorter periods at pH = 1.3 and pH = 9.4, which may be related to the type of electrostatic interactions between drug and polymer systems and their reactions with release solution ions.