In vitro and in vivo evaluation of curcumin loaded hollow microspheres prepared with ethyl cellulose and citric acid

In Vitro and In Vivo Evaluation of Composite Oral Fast Disintegrating Film: An Innovative Strategy for the Codelivery of Ranitidine HCl and Flurbiprofen

Here, we evaluate the feasibility of co-loading plain ranitidine hydrochloride (RHCl) and microencapsulated flurbiprofen (FBP) in a Lycoat^® RS780-based oral fast disintegrating film (ODF). These films were developed by the solvent casting method to minimize the adverse effects of FBP and reduce the dosage form burden on patients. Optimized FBP microparticles (M3) with an average size of 21.2 ± 9.2 µm were loaded alone (F1) and in combination with plain RHCl (F2) in the composite ODF. All films were evaluated physicomechanically and physicochemically. These films were resilient, flexible, and disintegrated within thirty seconds. SEM images showed intact FBP microparticles in both formulations and, moreover, did not observe an interaction between the drug and film components. Microencapsulated FBP was released in a controlled manner over 48 h from the proposed formulations, while RHCl was released within 5 min from F2. After in vitro evaluation, formulations were also tested for in vivo anti-inflammatory activity, cytokine (TNF-α and IL-6) levels, and gastroprotective effects in rats. The anti-inflammatory activity and gastroprotective effect of F2 were markedly higher than pure FBP and other synthesized formulations (M3 and F1). The average score of gastric lesions was in the order of pure FBP (15.5 ± 1.32) > M3 (8 ± 2) > F1 (1 ± 0.5) > F2 (0.5 ± 0) > control (0). Additionally, F2 showed a sustained anti-inflammatory effect up to 10 h in the rat paw edema model. Furthermore, F2 also markedly reduced TNF-α and IL-6 levels. Conclusively, the Lycoat^® RS780-based composite film could be a promising carrier for the co-loading of microencapsulated FBP with RHCl. In the future, an optimized formulation (F2) could be capable of countering the issues related to multiple drug administration in geriatric patients and evading the gastric irritation associated with FBP.

One-step emulsification for controllable preparation of ethyl cellulose microcapsules and their sustained release performance

A simple and versatile strategy for controlled production of monodisperse ethyl cellulose (EC) microcapsules by a single-stage emulsification method has been developed. Monodisperse oil-in-water emulsions, obtained by a microfluidic device, are used as templates for preparing EC microcapsules. Oil-soluble ethyl acetate (EA) is miscible with water, so the interfacial mass transfer between EA and water occurs sufficiently, which leads to water molecules pass through the phase interface and diffuse into emulsion interior. Water molecules aggregate at the interface, and some merge into a large water drop in the central position of the emulsion. After evaporation of EA solvent, monodisperse EC microcapsules create large numbers of pits on the surface with a hollow structure. Curcumin is used as a model drug and embedded in the hollow structure. EC microcapsules have good, sustained drug release efficacy in a simulated intestinal environment, and the release process of EC microcapsules containing 6.14% drug-loaded capacity is fully consistent with the vitro drug release model. Such simple techniques for making EC microcapsules may open a window to the controlled preparation of other multifunctional microcapsules. Besides, it offers theoretical guidance for the study of EC microcapsules as drug carriers and expanding clinical application of curcumin.

Preparation of Curcumin-Eudragit® E PO Solid Dispersions with Gradient Temperature through Hot-Melt Extrusion

Hot-melt extrusion (HME) has great advantages for the preparation of solid dispersion (SD), for instance, it does not require any organic solvents. Nevertheless, its application to high-melting-point and thermosensitive drugs has been rarely reported. In this study, thermally unstable curcumin (Cur) was used as a drug model. The HME process was systematically studied by adjusting the gradient temperature mode and residence time, with the content, crystallinity and dissolution of Cur as the investigated factors. The effects of barrel temperature, screw speed and cooling rate on HME were also examined. Solubility parameters and the Flory-Huggins method were used to evaluate the miscibility between Cur and carriers. Differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, equilibrium solubility and in vitro and in vivo experiments were used to characterize and evaluate the results. An amorphous Cur SD was successfully obtained, increasing the solubility and release of Cur. In the optimal process, the mass ratio of Cur to Eudragit® E PO (EPO) was 1:4 and the barrel temperature was set at a gradient heating mode (130 °C-135 °C-140 °C-145 °C-150 °C-155 °C-160 °C) at 100 rpm. Related pharmacokinetic test results also showed the improved bioavailability of the drug in rats. In a pharmacodynamic analysis of Sprague-Dawley rats, the Cmax and the bioavailability of the Cur-EPO SD were 2.6 and 1.5 times higher than those of Cur, respectively. The preparation of the amorphous SD not only provided more solubility but also improved the bioavailability of Cur, which provides an effective way to improve the bioavailability of BCS II drugs.

Onion Epithelial Membrane Scaffolds Transfer Corneal Epithelial Layers in Reconstruction Surgery

Plants and their extracts have been used especially in China for more than ten centuries for preventing and treating disease. However, there are only few reports describing their use in animal cell culture and tissue transplantation. In this study, onion epithelial membranes (OEM) is used as scaffolds to support cultures of a variety of cells such as fibroblasts and epithelial cells notably; they maintain the phenotypic characteristics of corneal epithelial cells. This improvement includes preservation of the proliferative potential and stemness of rabbit corneal epithelial cells (RCECs). Such an outcome suggests that this cost-effective technology warrants further evaluation to determine if OEM is a viable candidate for use as scaffolds in corneal epithelial transplantation surgery. To test this possibility, rabbit corneal epithelial cells expanded on OEM are transplanted to treat corneal epithelial defects in limbal stem cell deficient rabbits. This procedure is successful because it shortens the time required for wound healing to restore losses in corneal epithelial integrity, and forms a more compact and stratified epithelium framework than the untreated group. Ultimately, should they be proven to be effective in other relevant animal model systems, their usefulness for treating wounds in a clinical setting warrants consideration.

Dietary Curcumin: Correlation between Bioavailability and Health Potential

The yellow pigment curcumin, extracted from turmeric, is a renowned polyphenol with a broad spectrum of health properties such as antioxidant, anti-inflammatory, anti-cancer, antidiabetic, hepatoprotective, anti-allergic, anti-dermatophyte, and neuroprotective. However, these properties are followed by a poor pharmacokinetic profile which compromises its therapeutic potential. The association of low absorption by the small intestine and the extensive reductive and conjugative metabolism in the liver dramatically weakens the oral bioavailability. Several strategies such as inhibition of curcumin metabolism with adjuvants as well as novel solid and liquid oral delivery systems have been tried to counteract curcumin poor absorption and rapid elimination from the body. Some of these drug deliveries can successfully enhance the solubility, extending the residence in plasma, improving the pharmacokinetic profile and the cellular uptake.