Enteric coated spheres produced by extrusion/spheronization provide effective gastric protection and efficient release of live therapeutic bacteria

Probiotics Encapsulated via Biological Macromolecule for Neurological Therapy and Functional Food: A Review

Probiotics are live microorganisms that confer health benefits to humans, offering significant potential for preventing and treating various diseases. Neurological disorders, driven by multifaceted factors and linked to high disability rates, have become a growing global concern, particularly in the context of an aging population. Recent studies emphasize a strong connection between dysbiosis of the gut microbiota and neurological disorders. Probiotics have emerged as promising therapeutic interventions due to their ability to modulate the gut microbiota and influence the production of key metabolites, such as short-chain fatty acids and neurotransmitters, crucial for neurological health. However, probiotic viability is often compromised, limiting their therapeutic efficacy. We propose that developing high-activity probiotic formulations, coupled with innovative delivery strategies, holds considerable promise for advancing neurological treatments. Encapsulation systems have proven effective in enhancing probiotic stability and efficacy. This review discusses advances in probiotic delivery using biological macromolecule-based encapsulation, addressing key challenges in maintaining viability during production, storage, and digestion. It also highlights emerging delivery systems, such as microencapsulation, aimed at improving stability and therapeutic effectiveness. Additionally, the review explores the potential of functional foods enriched with probiotics for neurological health. Future research should explore clinical applications of encapsulated probiotics and support the development of functional foods to enhance neurological health.

Recent advances in bacteria-based platforms for inflammatory bowel diseases treatment

Inflammatory bowel disease (IBD) is a recurring chronic inflammatory disease. Current treatment strategies are aimed at alleviating clinical symptoms and are associated with gastrointestinal or systemic adverse effects. New delivery strategies are needed for the treatment of IBD. Bacteria are promising biocarriers, which can produce drugs in situ and sense the gut in real time. Herein, we focus on recent studies of engineered bacteria used for IBD treatment and introduce the application of engineered bacteria in the diagnosis. On this basis, the current dilemmas and future developments of bacterial delivery systems are discussed.

Precise oral delivery systems for probiotics: A review

Probiotics have several health benefits to the host. However, low pH in the stomach, various digestive enzymes and bile salts in the intestine threaten their viability and function. Thus, probiotics need to be protected during gastric transit to address challenges associated with low viability and impaired function. At present, probiotic delivery systems with different trigger mechanisms have been constructed to successfully introduce numerous high-viability probiotics to the intestine. On this basis, the application of non-targeted/targeted probiotic delivery systems in different gut microenvironment and the adjuvant therapeutic effect of probiotic delivery systems on other disease were discussed in detail. It is important to also note that most of the current studies in this area focused on non-targeted probiotic delivery systems. Moreover, changes in intestinal microenvironment under disease state and discontinuous distribution of disease site limit their development. Thus, emphasis were made on the optimization of non-targeted probiotic delivery systems and the necessity of designing more precisely targeted ones.

Intestinal Bacteria Encapsulated by Biomaterials Enhance Immunotherapy

The human intestine contains thousands of bacterial species essential for optimal health. Aside from their pathogenic effects, these bacteria have been associated with the efficacy of various treatments of diseases. Due to their impact on many human diseases, intestinal bacteria are receiving increasing research attention, and recent studies on intestinal bacteria and their effects on treatments has yielded valuable results. Particularly, intestinal bacteria can affect responses to numerous forms of immunotherapy, especially cancer therapy. With the development of precision medicine, understanding the factors that influence intestinal bacteria and how they can be regulated to enhance immunotherapy effects will improve the application prospects of intestinal bacteria therapy. Further, biomaterials employed for the convenient and efficient delivery of intestinal bacteria to the body have also become a research hotspot. In this review, we discuss the recent findings on the regulatory role of intestinal bacteria in immunotherapy, focusing on immune cells they regulate. We also summarize biomaterials used for their delivery.

Performance of reduced fat-reduced salt fermented sausage with added microcrystalline cellulose, resistant starch and oat fiber using the simplex design

The search for ingredients that improve technological and nutritional aspects of food has been intensified in recent years by both researchers and industry. Thus, the aim of this study was to evaluate fermented sausages with simultaneous reduction of fat (25%) and salt (25% KCl; 75% NaCl) using up to 2% of three different dietary fiber: microcrystalline cellulose (MCC), resistant starch (RS) and oat fiber (OF). Technological and sensory evaluations used the simplex-centroid mixture design. The dietary fiber added did not affect the weight loss, pH values and sensory acceptance. Models were obtained for water activity, lactic acid bacteria, hardness, chewiness and TBARS values. When included in combination the three dietary fiber helped reduce water activity, inclusion of MCC increased the population of lactic acid bacteria, and inclusion of OF with MCC demonstrated an antioxidant effect and improved hardness and chewiness. These dietary fibers are ingredients that can contribute to the development of reduced fat - reduced salt fermented sausage.

Achieving delayed release of freeze-dried probiotic strains by extrusion, spheronization and fluid bed coating - evaluated using a three-step in vitro model

Intake of probiotics is associated with many health benefits, which has generated an interest in formulating viable probiotic supplements. The present study had two aims. The first aim was to achieve gastrointestinal protection and delayed release of viable probiotics by pelletizing and coating freeze-dried probiotic strains, using riboflavin as a marker for release. The second aim was to set up a dynamic three-step in vitro model simulating the conditions in the human gastric, duodenum/jejunum and ileum compartments using physiologically relevant media to evaluate delayed release of the formulations. To simulate lowered bile acid concentrations in the ileum area of the gastrointestinal tract, a novel method using the bile acid sequestrant cholestyramine to lower bile acid concentrations in the small intestinal medium to physiologically relevant levels was attempted. Granulation, extrusion and spheronization was used to develop pellets containing viable probiotics using freeze-dried Lactobacullus reuteri as a model strain. Fluid bed coating the pellets with the pH-sensitive polymers Eudragit S100 or Eudragit FS30D resulted in targeted release in the ileum step of the three-step in vitro model based on release of the marker riboflavin.

Incorporation of Bifidobacterium sp. into powder products through a fluidized bed process for enteric targeted release

Considering the increase in evidence regarding the benefits of probiotics on human health, there is interest in developing solid products with proper functional characteristics, such as temperature and pH stability, that can be added to oral solid dosage forms or to dairy products to release microorganisms directly at their site of action. The aim of this work was to develop a product with an enteric coat containing probiotics that is stable at room temperature and resists low pH to ensure that the probiotics are passed through the stomach and reach the colon. We obtained 2 enteric-release products based on the incorporation of Bifidobacterium sp. using commercial microcrystalline cellulose (BIP-Av) and prebiotic inulin (BIP-In) as cores. Both products had an initial concentration of approximately 1 × 10⁸ bifidobacteria per gram (cfu/g) and showed a suitable resistance to acid; complete release from the products at a pH of 7.5 was observed at 120 min for BIP-In and 180 min for BIP-Av. The viability of bacteria in both products decreased by approximately 3 orders of magnitude. The death rate constant corresponded to 0.1143 for BIP-Av and 0.1466 for BIP-In, which means that in these storage conditions, the viability decreased slightly. Both products protected bifidobacteria for more than 2 yr, delivering a concentration of more than 1 × 10⁵ cfu/g. Due to these characteristics, the products could be incorporated into solid pharmaceutical forms for oral administration. These products could have significant advantages over existing products on the market and provide protection for bacteria, allowing their passage through the stomach to reach the colon, and the viability of bacteria was maintained after storage at room temperature for more than 1 yr.

Systematic Development of Bicalutamide Immediate Release Pellets Using Aeroperl and Non-MCC Extruder Aid

Background:

The Microcrystalline Cellulose is called as a gold standard for the manufacture of pellets. The poor disintegration leads to incomplete drug release that restricts the use of MCC in the immediate-release formulation.

Objective:

The present work aims to explore non-MCC extruder aid for pellet formulation and solubility modulation potential of Aeroperl® 300 Pharma.

Methods:

Bicalutamide (BCL) was selected as a model BCS class-II drug. The solubility of BCL was assessed in different vehicles such as polyethylene glycol, propylene glycol, and Tween by carrying out phase solubility study. The suitable vehicle was selected based on the higher solubility of BCL. The vehicle was further adsorbed on newer adsorbent Aeroperl® 300 Pharma to formulate liquisolid granules. The liquisolid granules were further incorporated into the pellet using mannitol and microcrystalline cellulose as an extruder aid. Box-Behnken design was adopted for the optimization of formulation considering MCC: mannitol ratio, the concentration of HPMC and spheronizer speed as independent factors whereas drug release at 30 min, disintegration time and aspect ratio were selected as dependent variables. The pellets were evaluated for different evaluation parameters.

Results:

Propylene glycol was selected for the formulation of liquisolid technique based on the results of the phase solubility study. Propylene glycol containing BCL was adsorbed on Aeroperl 300 Pharma. The optimized batch was selected exploring the Design-Expert software by considering the limits of different responses. Pellet had excellent flowability. Friability was found to be within the range (<1%). Pellets were found to be spherical and had pores on the surfaces.

Conclusion:

Liquisolid granules containing newer solubilizer Aeroperl was found to be a promising approach for the improvement in the solubility of the drug. The use of mannitol with MCC has a profound effect on disintegration time, without altering flow property and other parameters. No patents were reported on the combination of Bicalutamide, mannitol and Aeroperl. The critical finding of the present work is to use mannitol as an extruder aid to fasten the disintegration leads to complete drug release within a short period of time. Aeroperl and Mannitol, MCC: mannitol ratio, the concentration of HPMC and spheronizer speed were found to be significant and had the potential effect in pellet formulation.

On-Demand Bacterial Reactivation by Restraining within a Triggerable Nanocoating

Bacteria have been widely exploited as bioagents for applications in diagnosis and treatment, benefitting from their living characteristics including colonization, rapid proliferation, and facile genetic manipulation. As such, bacteria being tailored to perform precisely in the right place at the right time to avoid potential side effects would be of great importance but has proven to be difficult. Here, a strategy of on-demand bacterial reactivation is described by individually restraining within a triggerable nanocoating. Upon reaching at a location of interest, nanocoatings can be triggered to dissolution in situ and subsequently decoat the bacteria which are able to recover their bioactivities as needed. It is demonstrated that gut microbiota coated with an enteric nanocoating can respond to gastrointestinal environments and reactivate in the intestine by a pH-triggered decoating. In virtue of this unique, coated bacteria remain inactive following oral administration to exempt acidic insults, while revive to restore therapeutic effects after gastric emptying. Consequently, improved oral availability and treatment efficacy are achieved in two mouse models of intestinal infection. Bacteria restrained by a triggerable nanocoating represent a smart therapeutic that can take effect when necessary. On-demand bacterial reactivation suggests a robust platform for the development of precision bacterial-mediated bioagents.

Optimal conditions for the encapsulation of Weissella cibaria JW15 using alginate and chicory root and evaluation of capsule stability in a simulated gastrointestinal system

The delivery of active probiotic cells in capsules can reduce probiotic cell loss induced by detrimental external factors during digestion. In this study, we determined the optimal conditions for the encapsulation of Weissella cibaria JW15 (JW15) within calcium and polyethylene glycol (PEG)-alginate with chicory root extract powder (CREP). JW15 was encapsulated as the core material (109 cells/mL, 2 mL/min), and a solution containing a mixture of 1.5% sodium alginate and 1% CREP was extruded into a receiving bath with 0.1 M calcium chloride (CaCl2 ) and 0.05% PEG. Capsule morphology and size were measured using optical microscopy. The optimal air pressure and frequency vibration for capsules containing alginate only (Al) were 200 mbar and 200 Hz, respectively and 100 mbar and 350 Hz for capsules containing alginate with CREP (Ch), respectively. The voltage for both capsules types was fixed at 1.35 kV. Then, the capsules were incubated in a simulated gastrointestinal (GI) system for 6 hr at 37 °C. The addition of PEG in a CaCl2 hardening solution led to degradation of the Ch capsule (Ch-PEG) and the release of cells into the small intestine vessel in the simulated GI system. By contrast, the cells were trapped within the Al capsules. Based on these data, effective encapsulation using alginate with CREP and PEG can enable JW15 to be released at a targeted anatomical site of activity within the GI system, thereby, enhancing the efficacy of probiotic cells. These protective effects can be leveraged during the development of probiotic products. PRACTICAL APPLICATION: Weissella cibaria JW15 (109 cells/mL) was encapsulated in biodegradable and biocompatible capsules, prepared by mixing 1.5% alginate with 1% chicory root extract powder (CREP) in 0.1 M CaCl2 and 0.05% PEG using an encapsulator. The optimal processing parameters were as follows: pressure, 100 mbar; vibration frequency, 350 Hz; voltage, 1.35 kV; and core flow rate, 2 mL/min. When the resulting capsules were subjected to a simulated gastrointestinal system for 6 hr, the cells were released into the small intestine, and up to 95% cell viability was preserved. These results suggest that capsules made from alginate with CREP and formulated using calcium and PEG are a promising delivery system for probiotic cells.

Encapsulation of Escherichia coli strain Nissle 1917 in a chitosan-alginate matrix by combining layer-by-layer assembly with CaCl2 cross-linking for an effective treatment of inflammatory bowel diseases

Escherichia coli strain Nissle 1917 (EcN) has been widely shown to effectively treat inflammatory bowel diseases (IBDs). Unfortunately, after oral administration, EcN viability dramatically decreases due to severe environmental factors, including low gastric pH, temperature and osmotic pressure. To address these challenges and improve oral bio-availability, this study utilized layer-by-layer assembly (LbL) and ionic cross-linking with CaCl₂ as a method of EcN encapsulation (GEcN). Upon examination, GEcN cells were shown to maintain their ability to grow and proliferate, but had a slightly longer stationary phase (10 h) relative to free EcN (4 h). When exposed to simulated gastric fluid (SGF), a higher number of GEcN cells survived up to 12 h when compared to the other groups. To assess the therapeutic effect of EcN encapsulation in vivo, a TNBS-induced colitis rat model was established. When compared with the oral administration of free EcN, GEcN exhibited a significantly enhanced anti-inflammatory effect. Furthermore, GEcN treatment showed a lower disease activity index (DAI), decreased pro-inflammatory cytokine expression (MPO, TNF-α, IL-6) and increased anti-inflammatory cytokine expression (IL-10). Additionally, rats that received GEcN had much higher ZO-1 expression levels. These results suggest that EcN encapsulation in a chitosan-alginate matrix when utilizing the LbL assembly with CaCl₂ cross-linking can improve probiotic viability in a gastric environmental and thereby offer a more effective treatment for IBDs.

Polymeric carriers for enhanced delivery of probiotics

Probiotics are live microorganisms (usually bacteria), which are defined by their ability to confer health benefits to the host, if administered adequately. Probiotics are not only used as health supplements but have also been applied in various attempts to prevent and treat gastrointestinal (GI) and non-gastrointestinal diseases such as diarrhea, colon cancer, obesity, diabetes, and inflammation. One of the challenges in the use of probiotics is putative loss of viability by the time of administration. It can be due to procedures that the probiotic products go through during fabrication, storage, or administration. Biocompatible and biodegradable polymers with specific moieties or pH/enzyme sensitivity have shown great potential as carriers of the bacteria for 1) better viability, 2) longer storage times, 3) preservation from the aggressive environment in the stomach and 4) topographically targeted delivery of probiotics. In this review, we focus on polymeric carriers and the procedures applied for encapsulation of the probiotics into them. At the end, some novel methods for specific probiotic delivery, possibilities to improve the targeted delivery of probiotics and some challenges are discussed.

Using zeta potential to study the ionisation behaviour of polymers employed in modified-release dosage forms and estimating their pKa

A range of enteric polymers is used in pharmaceutical industry for developing gastro-resistant formulations. It is generally implied that these coatings are interchangeable due to similar dissolution pH thresholds reported by suppliers. Despite rapid dissolution in compendial phosphate buffers, these products can take up to 2 h to disintegrate in-vivo in the human small intestine. The factors primarily responsible for such variability in dissolution of these polymeric coatings are the differences in ionisation of acidic functional groups on polymer chains and their interplay with ions and buffer species present in gastrointestinal fluids. In this study, we aim to develop a novel, simple and inexpensive technique that can be used under various in-vitro conditions to study the ionisation behaviour of commonly used polymers (EUDRAGIT-E100, L100, S100, HPMC AS-LF, AS-HF, HP-50, HP-55) and to estimate their pK_a. Moreover, this method was successfully applied to study the ionisation behaviour of a range of natural polymers (Guar, Tara, locust bean, Konjac gums, gum Arabic, citrus pectin, chitosan and alginate) and their pK_a was also estimated. The proposed method would allow a better understanding of the dissolution behaviour of these polymers within gastrointestinal tract and will aid rational design of modified release dosage forms.

Preparation, Characterization and Pharmacokinetics Evaluation of the Compound Capsules of Ibuprofen Enteric-Coated Sustained-Release Pellets and Codeine Phosphate Immediate-Release Pellets

The objective of this study was to prepare ibuprofen enteric-coated sustained-release pellets (IB-SRPs) and codeine phosphate immediate-release pellets (CP-IRPs) to play a synergistic role in analgesia. The pellets were developed by extrusion-spheronization and fluidized bed coating technology. The single-factor investigation was used to determine the optimal prescription and process. The sustained-release membrane of IB-SRPs was water-insoluble ethyl cellulose (EC), triethyl citrate (TEC) was used as plasticizer, and hydroxypropyl methylcellulose (HPMCP) was chose as porogen. Besides, the immediate-release layer of CP-IRPs was gastric-soluble coating film. The ibuprofen and codeine phosphate compound capsules (IB-CP SRCs) were prepared by IB-SRPs and CP-IRPs packed together in capsules with the optimum doses of 200 and 13 mg, respectively. The prepared pellets were evaluated by scanning electron microscopy and dissolution test. Pharmacokinetic studies in beagle dogs indicated that the optimized IB-CP SRCs had smaller individual differences and better reproducibility comparing with commercial available tablets. Additionally, IB-CP SRCs achieved consistency with in vivo and in vitro tests. Therefore, IB-CP SRCs could play a great role in rapid and long-term analgesic.

Improving in vivo conversion of oleuropein into hydroxytyrosol by oral granules containing probiotic Lactobacillus plantarum 299v and an Olea europaea standardized extract

This study reports novel food-grade granules for co-delivery of L. plantarum 299v and a standardized extract of Olea europaea leaves (Phenolea®) as oral carrier of probiotics and hydroxytyrosol. Different granule formulations containing either L. plantarum 299v (Lac), or the olive leave extract (Phe) or their combination (Lac-Phe) have been successfully produced through wet granulation employing excipients generally regarded as safe as granulating/binding agents. L. plantarum cells withstood the manufacturing process and were stable upon storage at 4 °C for more than 6 months. In vitro dissolution studies in simulated gastro-intestinal fluids showed the capability of the granules to rapidly dissolve and deliver both olive leave phenols and living L. plantarum cells. In simulated digestion conditions, Lac and Lac-Phe granules protected L. plantarum against the harsh environment of the gastro-intestinal tract. Co-administration of Lac and Phe oral granules to healthy mice provided for higher amounts of hydroxytyrosol in urines as compared to Phe granules alone, suggesting that L. plantarum 299v boosted in vivo conversion of oleuropein to hydroxytyrosol. On the other hand, PCR-assisted profiling of the Lactobacillus population in faeces obtained from mice treated with Lac or Lac plus Phe confirmed that the probiotic arrived alive to colon and was there able to exert a sort of perturbing effect on the climax colonic microflora. Overall, these results pave the way towards the development of a nutraceutical useful for combined delivery of bioactive hydroxytyrosol and probiotics to colon site.

Functionality and nutritional aspects of microcrystalline cellulose in food

Microcrystalline cellulose (MCC) is among the most commonly used cellulose derivatives in the food industry. In order assess the recent advances of MCC in food product development and its associated nutraceutical implications, google scholar and database of journals subscribed by Jiangnan university, China were used to source literature. Recently published research articles that reported physicochemical properties of MCC for food application or potential application in food and nutraceutical functions were reviewed and major findings outlined. The selected literature reviewed demonstrated that the material has been extensively explored as a functional ingredient in food including meat products, emulsions, beverages, dairy products, bakery, confectionary and filling. The carbohydrate polymer also has many promising applications in functional and nutraceutical food industries. Though widely used as control for many dietary fiber investigations, MCC has been shown to provide positive effects on gastrointestinal physiology, and hypolipidemic effects, influencing the expression of enzymes involved in lipid metabolism. These techno-functional and nutraceutical properties of MCC are influenced by the physicochemical of the material, which are defined by the raw material source and processing conditions. Apart from these functional properties, this review also highlighted limitations and gaps regarding the application of material in food and nutritional realms. Functional, Nutritional and health claims of MCC.

Microencapsulation in Alginate and Chitosan Microgels to Enhance Viability of Bifidobacterium longum for Oral Delivery

Probiotic microorganisms are incorporated into a wide variety of foods, supplements, and pharmaceuticals to promote human health and wellness. However, maintaining bacterial cell viability during storage and gastrointestinal transit remains a challenge. Encapsulation of bifidobacteria within food-grade hydrogel particles potentially mitigates their sensitivity to environmental stresses. In this study, Bifidobacterium longum subspecies and strains were encapsulated in core-shell microgels consisting of an alginate core and a microgel shell. Encapsulated obligate anaerobes Bifidobacterium longum subsp. infantis and Bifidobacterium longum subsp. longum exhibited differences in viability in a strain-dependent manner, without a discernable relationship to subspecies lineage. This includes viability under aerobic storage conditions and modeled gastrointestinal tract conditions. Coating alginate microgels with chitosan did not improve viability compared to cells encapsulated in alginate microgels alone, suggesting that modifying the surface charge alone does not enhance delivery. Thus hydrogel beads have great potential for improving the stability and efficacy of bifidobacterial probiotics in various nutritional interventions.