Genipin, a natural and non-toxic cross linker, was used to prepare cross linked floating kappa carrageenan/sodium carboxymethyl cellulose hydrogels and the effect of genipin on hydrogels characterization was investigated. Calcium carbonates were employed as gas forming agents. Ranitidine hydrochloride was used as drug. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were carried out to study the changes in the characteristics of hydrogels. Furthermore, scanning electron microscope (SEM) was performed to study microstructure of hydrogels. The result showed that all formulated hydrogels had excellent floating behavior. It was discovered that the cross linking reaction showed significant effect on gel strength, porosity and swelling ratio compared to non-cross linked hydrogels. It was found that the drug release was slower and lesser after being cross linked. Microstructure study shows that cross linked hydrogels exhibited hard and rough surface. Therefore, genipin can be an interesting cross linking agent for controlled drug delivery in gastrointestinal tract.
Floating hydrogels were prepared from kappa carrageenan containing CaCO3 and NaHCO3 as pore forming agents. The effects of CaCO3 and NaHCO3 on hydrogel characterizations were investigated and compared. Amoxicillin trihydrate was used as a model drug. Characterizations of the hydrogels were carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). As pore forming agents concentration increases, the porosity (%) and floating properties increased. NaHCO3 incorporated hydrogels showed higher porosity with shorter floating lag time (FLT) than CaCO3. Hydrogel which contained CaCO3 exhibited better gel stability over the control and NaHCO3 containing gel. Incorporation of CaCO3 into kappa carrageenan hydrogel showed smoother surface gels compared to those produced with NaHCO3. CaCO3 also showed higher drug entrapment efficiency and sustained drug release profile than NaHCO3. The results of these studies showed that, CaCO3 is an effective pore forming agents in κC hydrogels preparation as compare to NaHCO3. Thus, CaCO3 can be an excellent pore forming agent for an effective floating drug delivery system.
The purpose of this study was to investigate the preparation of formulated water- in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using a cellulose acetate membrane. The effect of selective membrane emulsification process parameters (concentration of the emulsifiers, number of passes of the emulsions through the membrane and storage temperature) on the properties and stability of the developed emulsions were also investigated. 1, 3, 6, 8-pyrenetetrasulfonic acid tetrasodium salt (PTSA) was used as a hydrophilic model ingredient for the encapsulation of bioactive substances. W/O emulsions with 7 wt% (weight percentage) PGPR displays homogeneous and very fine dispersions, with the median diameter at 0.640 μm. Meanwhile, emulsions prepared by membrane emulsification (fine W/O/W) showed the highest stability at Tween 80 concentrations of 0.5 wt.% (weight percentage). It concluded that at 7 wt.% (weight percentage) PGPR concentration and 0.5 wt.% (weight percentage) Tween 80 concentrations, the most uniform particles with minimum mean size of oil drops (9.926 μm) were obtained after four passes through the membrane. Thus, cellulose acetate membrane can be used for preparing a stable W/O/W emulsions by repeated premix ME due to low cost and relatively easy to handle.