Development and evaluation of floating alginate microspheres for oral delivery of anthocyanins - A preliminary investigation

Exploration of Cassia fistula L. seed mucilage into floating drug delivery system

The aim of the present study was to explore Cassia fistula L. seed mucilage as a natural polymer in controlled release floating drug delivery system. First, seed mucilage was extracted and evaluated for phytochemical screening, solubility studies, swelling index, viscosity and surface tension. Then, Atenolol floating systems were prepared with and without the C. fistula L. seed mucilage by direct compression method. Phytochemical screening resulted from the presence of secondary metabolite carbohydrates, glycosides, flavonoids and phenolic compounds in good amounts. Results of hardness, friability, drug content and swelling index were satisfactory. The floating behaviour can increase the gastric residence time and eventually improve the bioavailability of the drug as evidence from in vitro buoyancy and dissolution studies. Interestingly, developed floating system showed remarkable increase in dissolution. Conclusively, the results suggest that developed Atenolol floating system with C. fistula L. seed mucilage demonstrate interesting attributes to be explored for potential pharmaceutical application.

Bacteria-Loaded Gastro-Retention Oral Delivery System for Alcohol Abuse

Alcohol abuse is harmful to human health, and many strategies have been developed to retard this harm through protecting liver or activating relative enzymes. In this study, a new strategy of decreasing the alcohol absorption directly depending on the dealcoholization by the bacteria in the upper gastrointestinal (GI) tract was reported. To realize this, a bacteria-loaded gastro-retention oral delivery system with pore structure was constructed through emulsification/internal gelation, which could relieve acute alcohol intoxication in mice successfully. It was found that this bacteria-loaded system kept the above 30% suspension ratio in the simulated gastric fluid for 4 min, displayed good protection effect for the bacteria, and decreased the alcohol concentration from 50 to 30% below within 24 h in vitro. The in vivo imaging results demonstrated that it remained in the upper GI tract until 24 h and reduced 41.9% alcohol absorption. The mice with oral administration of the bacteria-loaded system were found with normal gait, smooth coat, and less liver damage. Although the intestinal flora distribution was influenced slightly during the oral administration, it could restore to normal levels only one day after stopping oral administration quickly, suggesting good biosafety. In conclusion, these results revealed that the bacteria-loaded gastro-retention oral delivery system might intake alcohol molecules rapidly and has huge potential in the treatment of alcohol abuse.

Fluorescent Polyelectrolyte System to Track Anthocyanins Delivery inside Melanoma Cells

Over the past decades, there has been a growing interest in using natural molecules with therapeutic potential for biomedical applications. In this context, our aim is focused on anthocyanins (AN) as molecules with anticancer properties that could be used in melanoma local therapies. Due to their susceptibility to environmental changes, current study is based on the design and development of a fluorescent system for carrying and trafficking AN inside melanoma cells. The architectural structure of the proposed system CaCO₃(PAH)@RBITC@AN reflects a spherical shape, 1080 nm diameter and a solid groundwork CaCO₃(PAH), on which rhodamine B isothiocyanate (RBITC) fluorophore was firstly added; then, poly(acrylic acid) (PAA) polyelectrolytes and poly(allylamine hydrochloride) (PAH) were successfully deposited. Purified AN from chokeberries were entrapped between PAA layers (rate of 94.6%). In vitro tests confirmed that CaCO₃(PAH)@RBITC@AN does not affect the proliferation of melanoma B16-F10 cells and proved that their internalization and trafficking can be followed after 24 h of treatment. Data presented here could contribute not only to the existing knowledge about the encapsulation technology of AN but also might bring relevant information for a novel formula to deliver therapeutic molecules or other bio-imaging agents directly into melanoma cells, a strategy that could positively improve tumor therapies.

Technologies and Formulation Design of Polysaccharide-Based Hydrogels for Drug Delivery

Polysaccharide-based hydrogel particles (PbHPs) are very promising carriers aiming to control and target the release of drugs with different physico-chemical properties. Such delivery systems can offer benefits through the proper encapsulation of many drugs (non-steroidal and steroidal anti-inflammatory drugs, antibiotics, etc) ensuring their proper release and targeting. This review discusses the different phases involved in the production of PbHPs in pharmaceutical technology, such as droplet formation (SOL phase), sol-gel transition of the droplets (GEL phase) and drying, as well as the different methods available for droplet production with a special focus on prilling technique. In addition, an overview of the various droplet gelation methods with particular emphasis on ionic cross-linking of several polysaccharides enabling the formation of particles with inner highly porous network or nanofibrillar structure is given. Moreover, a detailed survey of the different inner texture, in xerogels, cryogels or aerogels, each with specific arrangement and properties, which can be obtained with different drying methods, is presented. Various case studies are reported to highlight the most appropriate application of such systems in pharmaceutical field. We also describe the challenges to be faced for the breakthrough towards clinic studies and, finally, the market, focusing on the useful approach of safety-by-design (SbD).

Zinc and Calcium Cations Combination in the Production of Floating Alginate Beads as Prednisolone Delivery Systems

The aim of this research was to verify the application of alginate in combination with Ca²⁺ and Zn²⁺ ions to produce a floating and prolonged release system for the oral administration of prednisolone. Hollow and floating gel-beads were designed using prilling/ionotropic gelation as the microencapsulation technique, zinc acetate in the gelling solution as the alginate external crosslinker, and calcium carbonate in the feed as the internal crosslinking agent able to generate gas when in contact with the acidic zinc acetate solution. To achieve this goal, drug/alginate solutions were opportunely combined with different amounts of calcium carbonate. The effect of the addition of calcium carbonate into the feed solution on buoyancy, encapsulation efficiency, morphology, size distribution, as well as in vitro drug release profile of the alginate particles was studied. Moreover, the ability of the floating beads to modulate in vivo the anti-inflammatory response was assayed using the carrageenan-induced acute oedema in rat paw. The proposed strategy allowed obtaining alginate beads with extremely high encapsulation efficiency values (up to 94%) and a very porous inner matrix conferring buoyancy in vitro in simulated gastric fluid up to 5 h. Moreover, in vivo, the best formulation, F4, resulted in the ability to prolong the anti-inflammatory effect up to 15 h compared with raw prednisolone.

Development and evaluation of floating alginate microspheres for oral delivery of anthocyanins - A preliminary investigation

The goal of this study was to develop floating microspheres that could be used as gastroretentive systems for the delivery of anthocyanins (ACNs). These compounds are absorbed in the stomach and small intestine, and insufficient residence time in these organs could result in limited absorption and contribute to degradation. The microparticles containing freeze‐dried haskap berry extract (321.96 ± 8.35 mg cyanidin 3‐glucoside equivalents per g) were prepared by ionotropic gelation of alginate (9%, w/w) with calcium ions (CaCl₂ at 2%, w/v) in the gelation bath, with calcium carbonate as the gas‐generating compound (added at different ratios in the alginate/extract mixture). The effect of acetic acid concentration (2 and 10%, v/v) in the gelation medium was investigated. Increasing the carbonate : alginate weigh ratio from 0 to 3:4 resulted in different degrees of floatability, larger particles, higher encapsulation efficiency, and lower amount of ACN released. The power law equation fitted the experimental data well, indicating that release occurred mainly by diffusion. This is the first time floating microspheres are proposed as gastroretentive platforms for the delivery of ACNs.