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Capsules containing indomethacin as a model, poorly water-soluble drug, were produced using the unconventional high-M alginate polymer for site-specific drug delivery in the GI tract. Hydrated Calcium (Ca)-alginate capsules (3 mm diameter), produced by ionotropic gelation permitted almost complete release in simulated gastric fluid (SGF), at 37 °C in 2 h, offering a facile approach for extemporaneous preparation of immediate release formulations. Hydrated Zinc (Zn)-alginate capsules delivered 50% of the drug in SGF but almost zero in simulated intestinal fluid (SIF) over 6 h. Ca-alginate capsules dried at room temperature, hydrated Barium (Ba)-alginate capsules and hydrated Ca-alginate/guar gum capsules released 70% of the drug load in SIF, providing options for improving delivery efficiency in the small intestine. Hydrated Ba-alginate capsules resulted in a significant reduction in indomethacin release compared with Ca-alginate due to the binding affinity of Ba2+ for both M and G blocks in the high-M alginate chain. Ca-alginate capsules dried at 45 °C or freeze dried, restricted release to below 25% on sequential exposure to SGF and SIF and are potentially useful for targeting the diseased colon.

The aim of a chronotherapeutic medicine is to tailor drug in vivo availability to circadian rhythms of diseases in order to reduce side effects and improve patient compliance. To counteract morning symptoms of early morning pathologies, a drug delivery system able to delay ketoprofen release after oral administration has been proposed. Particles made of a pectin matrix were produced by means of prilling; core–shell systems were produced covering the drug particles with Eudragit S100 ® . The systems developed, containing different drug/polymer ratios, were fully characterized in terms of drug content, efficiency of encapsulation, morphology and drug release kinetics. The results indicated that the loading of larger amounts of drug in the feed solution led to spherical and mono-disperse beads, with high encapsulation efficiency and a reduced drug delivery in gastric simulated fluids (22%). Finally, a further delay of drug release (7.3% released in simulated gastric fluid) was achieved applying to the drug/pectin core a shell of Eudragit S100 ® (40% w/w) a gastro-resistant polymer. This core–shell platform exploits the different characteristics of the two selected polymers, i.e. pH dependent solubility of Eudragit S100 ® and the peculiarities of pectin, degraded slowly in alkaline environment and selectively by the intestinal microflora in vivo.

Complexes of amylose (AS) with ibuprofen (IBF) were prepared by the acidification method to yield V-type structure with different IBF-AS ratios. Among the ratios being tested, the IBF-AS ratio of 1/10 gave the highest yields (52.6%, w/w) and IBF content in the complex (14.1%, w/w). The XRD and 13 C CP/MAS NMR spectra indicated that the AS and IBF formed the V-amylose complexes. The DSC and FT-IR analysis further testified the formation of the AS-IBF inclusion complexes. These complexes are stable in simulated gastric fluid (pH 1.2), with

This work aims to develop and evaluate buoyant beads embedded with domperidone/Dowex 50WX2 resinate complex as novel multiple-unit type oral gastro-retentive drug delivery system. Domperidone (BCS II) has been chosen for gastric retention as it has a poor oral bioavailability (around 15%), a short biological half-life, and pH-dependent solubility with poor solubility at a high pH and good solubility at low pH. Two different techniques were used to induce beads buoyancy; first, formulation of effervescent beads by incorporation of NaHCO3 in the beads, which will release carbon dioxide gas upon reaction with the acidic gastric fluid causing the beads to float. Second, is the formation of low-density emulgel beads by the incorporation of light mineral oil in the beads. Resinate complex is used to control the drug release from the prepared formulations. Beads were evaluated for percent drug entrapment efficiency, floating behavior (float lag time and duration), mean particle diameter, in vitro drug release, and release kinetics in SGF. The effect of different concentrations of both NaHCO3 (1%, 2%, and 10%) and light mineral oil (2%, 5%, and 10%) on the floating behavior and physical appearance was studied. The optimized formula (F10) was subjected to a four-week stability study at both 25 oC and 40 oC. Results revealed that gastro-retentive beads possessed a floating duration of up to 24 hours and no floating lag time was developed. The novel resinate loaded beads succeeded to sustain the release of domperidone in SGF. The optimized formula was stable at both temperatures of 25 oC and 40 oC for four weeks. Hence, the developed optimized formulation (F10) is considered as a potential to increase the domperidone bioavailability, decrease dosage frequency, and increase patient compliance.

Purpose The present work aims to develop and characterize domperidone resinate complex to be loaded into a gastroretentive delivery system. The formed resinate complex will be used to control the drug release in the stomach from inside the gastroretentive delivery system. Methods Resinate complexes were formulated by a simple aqueous binding method. Screening of different types of resins was carried out. Domperidone binding study was tested at various drug and resin concentrations. Physicochemical characterizations were carried out to evaluate the prepared resinate complex. These studies included flow properties, in vitro drug release in simulated gastric fluid (SGF), Differential scanning calorimetry (DSC), Mass spectroscopy and XPRD evaluations. Also, the stability study of the selected resinate complex was conducted at 25 °C and 40 °C for up to one month. Results Domperidone and Dowex 50WX2 in a ratio of 1:3 have formed a resinate complex that has shown acceptable flow properties, thermal properties and short-term chemical stability at 25 °C and 40 °C. Domperidone release profile from resinate in SGF has shown slow controlled release characteristics. Conclusion The domperidone stable complex with Dowex ion exchange resin has the potential for further development as gastroretentive drug delivery system as a mean of controlling the drug release.

Bovine Serum Albumin (BSA) was encapsulated into pH-responsive alginate/kappa(κ)-carrageenan double network hydrogel beads at different pHs and CaCl2/KCl ratios. Controlled release of BSA was performed in the simulated gastric fluid (SGF) and then in simulated intestinal fluid (SIF). Alginate reinforced the mechanical properties while double network with kappa-carrageenan made slow down the release of BSA into SIF. Sulfate groups on kappa-carrageenan improved the resistivity against phosphate buffer solution. Encapsulation and BSA release was manipulated by varying pH and crosslinking concentration. The highest encapsulation efficiency (83–89%) was obtained with the hydrogel beads prepared at the lower pH than isoelectric point of BSA, then 67–72% of them released in SIF in 4–5 h while lower than 10% of BSA released in SGF, hence, protein delivery targeted intestinal was achieved. BSA release exhibited a coupling of diffusion and polymer relaxation mechanism without burst release.

Gastro-retentive drug delivery systems (GRDDS) provide prolonged drug release in the stomach for the treatment of some diseases located in the gastric area, and can improve patient compliance by reducing the required dosing frequency. In this study, floating 3D-printed devices combined with a commercial capsule of amoxicillin (Sia-Mox®) were developed for the treatment of H. Pylori infection. The floating 3D-printed devices (FPD) were fabricated using fused deposition modeling (FDM) 3D-printer with PVA filament followed by thermal crosslinking process. The morphology of the FPD was investigated by microscope. The water insolubilization, TGA and FT-IR were analyzed to confirm the successful crosslinking of the FPD. In vitro floating time and drug release in a simulated gastric fluid were determined using the USP dissolution apparatus II. The results showed that the floating time of the Sia-Mox® incorporated FPD was significantly longer than that of the conventional Sia-Mox® capsule, and that the floating time increased after the FPD was crosslinked. The optimal condition for the crosslinking of FPD was 140 °C for 6 h (FPD4). In vivo floating study in rabbit showed that the floating time of FPD4 was more than 10 h. The release of the drug from the Sia-Mox® in FPD4 fitted with the Higuchi model. Our results demonstrated that the development of FPD for GRDDS was successful, which the FPDs were able to float and prolong drug release.

Limonin and nomilin, the major limonoid components of pomelo [Citrus maxima (Burm.) Merr.] seeds, have been reported to be potential cancer chemopreventive agents, but their low aqueous solubility and limited bioavailability impede their applications as nutraceuticals. In this study, a zein-alginate encapsulation system was utilized to produce highly dispersible limonin and nomilin nanoparticles (172.7 ± 7.4 and 273.3 ± 2.3 nm dia., respectively) with high encapsulation efficiencies and high stabilities at both ambient and refrigerated storage conditions. In vitro release studies showed that the nanodelivery system can delay and minimize the release of the limonoids in simulated gastric fluid (SGF) and preferentially release these compounds in simulated intestinal fluid (SIF). Furthermore, zein-alginate encapsulated limonin and nomilin exhibited significantly improved glutathione S-transferase (GST)-inducing activity, free radical-scavenging activity, and anti-angiogenic activity. These results demonstrate that the zein-alginate complexes can serve as effective oral delivery system for limonin and nomilin.