DEVELOPMENT OF HYDROGELS TO ENCAPSULATE RED BETEL EXTRACT

• Main Author: Edikresnha, Dhewa
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/63818
• Institution: Institut Teknologi Bandung

Red betel leaves has been used traditionally to stop nosebleeds, treat burns, coughs, rheumatism, and as an antiseptic and to inhibit the growth of bacteria. The application for disease prevention or therapy requires a delivery medium to control the rate of drug release. This study aimed to develop a polyvinylalcohol (PVA) hydrogel as a delivery media for red betel leaf extract using the freeze-thaw technique to increase the therapeutic value of red betel leaf extract. PVA has been widely used in biomedical and biomaterial applications. In this study, the composition of the precursor solution was varied and the physical and morphological properties of the hydrogel were investigated. The red betel leaf was extracted with 70% ethanol (v/v) solvent, concentrated with a rotary evaporator, and then dried using a freeze-dry method. The precursor solution consisted of a mixture of PVA solution with extract solution at various compositions. The viscosity and density of the precursor solution decreased as the fraction of the extract solution increased, while the pH of the precursor solution increased with the increase in the fraction of the extract solution. The phase separation of solid and liquid phases of the dried gels was confirmed by observation on their cross section using electron microscopy. For hydrogel with the largest extract fraction, the extract appeared in the form of cube protrusions. Observed by FTIR analysis, the peaks of the functional group of the extract also appeared in the composite hydrogel so it can be concluded that the hydrogel sample was loaded with the extract. The crystallinity of the composit hydrogel was examined by XRD. It was found that the peak attributed to the semicrystalline nature of PVA powder decreased in intensity when the PVA was transformed into a hydrogel. In the FTIR spectrum, it can also be observed that for the larger fraction of extract resulted in the higher the peak in the wavenumber range from 3000 to 3800 cm-1 associated with the OH stretching vibration. The phase transformation from semicrystalline to amorphous when the PVA powder was synthesized into hydrogels was observed from the X-ray diffraction characterization, in which the diffuse scattering of X-rays by the liquid took place. On the TGA thermogram, there was a drastic weight reduction of the hydrogel in the early stages caused by the evaporation of the liquid. PVA hydrogel had a higher thermal stability than PVA powder as evidenced by higher decomposition temperature. From the DSC thermogram, the decrease in the PVA fraction caused the melting point of the PVA in the hydrogel to shift to a lower temperature and the total heat required to melt the PVA in the sample decreased. From the swelling degree test, pure hydrogel without extract had the highest degree of swelling, while the composite hydrogel with the largest extract fraction had the smallest degree of expansion due to the significant release of extract to the phosphate buffer saline liquid during the test. The results of the gel fraction test showed that the larger the extract fraction, the smaller the gel fraction in the hydrogel. The compressive modulus of the composite hydrogel decreased as the extract fraction increased. The antibacterial activity against Staphylococcus aureus was consistently higher than that of Pseudomonas aeruginosa for all hydrogel samples. The release of the extract from the sample followed a pseudo-fickian model, which meant that the extract was released through the process of diffusion from the hydrogel. When the extract fraction was the largest, the release of extract release was inhibited by the gap size between the polymer chains so that the hydrogel with the largest extract fraction exceeded the threshold of the Fickian diffusion model.