In Vitro Development of Enteric-Coated Tablets of the Probiotic Lactobacillus fermentum LF-G89: A Possible Approach to Intestinal Colonization

BACKGROUND

Probiotics must be able to withstand the demanding environment of the gastrointestinal system to adhere to the intestinal epithelium, promoting health benefits. The use of probiotics can prevent or attenuate the effects of dysbiosis that have a deleterious effect on health, promoting anti-inflammatory, immunomodulatory, and antioxidant effects.

OBJECTIVE

The aim of the study was to prepare tablets containing Lactobacillus fermentum LF-G89 coated with 20% Acryl-Eze II® or Opadry® enteric polymers.

METHODS

Tablet dissolution was evaluated under acidic and basic pH conditions, and aliquots of the dissolution medium were plated to count the Colony-forming Units (CFU). The free probiotic's tolerance to pH levels of 1.0, 2.0, 3.0, and 4.0, as well as to pepsin, pancreatin, and bile salts, was assessed.

RESULTS

The probiotic was released from tablets coated after they withstood the pH 1.2 acid stage for 45 minutes. The release was higher with the Acry-Eze II® polymer in the basic stage. The amount of CFU of free probiotics at pH 1.0 to 4.0 as well as pepsin reduced over time, indicating cell death. Conversely, the CFU over time with pancreatin and bile salts increased, demonstrating the resistance of L. fermentum to these conditions due to hydrolases.

CONCLUSION

Both coating polymers were able to withstand the acid step, likely ensuring the release of the probiotic in the small intestine, promoting colonization. Coating with enteric material is a simple and effective process to increase the survival of probiotics, offering a promising alternative to mitigate the negative effects of the dysbiosis process.

Process and formulation parameters influencing the survival of Saccharomyces cerevisiae during spray drying and tableting

Probiotic microorganisms provide health benefits to the patient when administered in a viable form and in sufficient doses. To ensure this, dry dosage forms are preferred, with tablets in particular being favored due to several advantages. However, the microorganisms must first be dried as gently as possible. Here, the model organism Saccharomyces cerevisiae was dried by spray drying. Various additives were tested for their ability to improve yeast cell survival during drying. In addition, the influence of various process parameters such as inlet temperature, outlet temperature, spray rate, spray pressure and nozzle diameter was investigated. It was possible to dry the yeast cells in such a way that a substantial proportion of living microorganisms was recovered after reconstitution. Systematic variation of formulation and process parameters showed that the use of protective additives is essential and that the outlet temperature determines the survival rate. The subsequent compression of the spray-dried yeast reduced viability and survival could hardly be improved by the addition of excipients, but the tabletability of spray-dried yeast protectant particles was quite good. For the first time, loss of viability during compaction of spray-dried microorganisms was correlated with the specific densification, allowing a deeper understanding of the mechanism of cell inactivation during tableting.

Development and evaluation of a fish feed mixture containing the probiotic Lactiplantibacillus plantarum prepared using an innovative pellet coating method

Introduction

Due to the intensification of fish farming and the associated spread of antimicrobial resistance among animals and humans, it is necessary to discover new alternatives in the therapy and prophylaxis of diseases. Probiotics appear to be promising candidates because of their ability to stimulate immune responses and suppress the growth of pathogens.

Methods

The aim of this study was to prepare fish feed mixtures with various compositions and, based on their physical characteristics (sphericity, flow rate, density, hardness, friability, and loss on drying), choose the most suitable one for coating with the selected probiotic strain Lactobacillus plantarum R2 Biocenol™ CCM 8674 (new nom. Lactiplantibacillus plantarum). The probiotic strain was examined through sequence analysis for the presence of plantaricin- related genes. An invented coating technology based on a dry coating with colloidal silica followed by starch hydrogel containing L. plantarum was applied to pellets and tested for the viability of probiotics during an 11-month period at different temperatures (4°C and 22°C). The release kinetics of probiotics in artificial gastric juice and in water (pH = 2 and pH = 7) were also determined. Chemical and nutritional analyses were conducted for comparison of the quality of the control and coated pellets.

Results and discussion

The results showed a gradual and sufficient release of probiotics for a 24-hour period, from 10⁴ CFU at 10 mi up to 10⁶ at the end of measurement in both environments. The number of living probiotic bacteria was stable during the whole storage period at 4°C (10⁸), and no significant decrease in living probiotic bacteria was observed. Sanger sequencing revealed the presence of plantaricin A and plantaricin EF. Chemical analysis revealed an increase in multiple nutrients compared to the uncoated cores. These findings disclose that the invented coating method with a selected probiotic strain improved nutrient composition and did not worsen any of the physical characteristics of pellets. Applied probiotics are also gradually released into the environment and have a high survival rate when stored at 4°C for a long period of time. The outputs of this study confirm the potential of prepared and tested probiotic fish mixtures for future use in in vivo experiments and in fish farms for the prevention of infectious diseases.

Influence of compression kinetics during tableting of fluidized bed-granulated microorganisms on microbiological and physical-mechanical tablet properties

As tablets are convenient to administer to patients, ensure safe dosing and allow cost-effective production on a large scale, they are the favored dosage form for numerous active pharmaceutical ingredients but also for the administration of viable probiotic microorganisms. Granules with viable yeast cells (Saccharomyces cerevisiae) formed by fluidized bed granulation with dicalcium phosphate (DCP), lactose (LAC) or microcrystalline cellulose (MCC) as carrier materials were tableted using a compaction simulator. Besides the compression stress, the compression speed was systematically studied by varying consolidation time and dwell time. The microbial survival as well as physical properties of the tablets, e.g., porosity and tensile strength, were determined. Higher compression stresses result in lower porosities. While on the one hand this has a detrimental effect on microbial survival (due to increased pressure and shear stress during particle rearrangement / densification), on the other hand it results in higher tensile strengths. At the same compression stress, a prolonged dwell time resulted in lower porosity and thus in lower survival rates but higher tensile strength. Against that, consolidation time showed no significant influence on the considered tablet quality attributes. Since changes of the tensile strength related survival rate were negligible (due to opposite but balancing dependence on porosity), high production speeds could be used for tableting of these granules without additional loss of viability, as long as tablets with the same tensile strength are produced.

Tableting of Fluidized Bed Granules Containing Living Microorganisms

Tablets are the favored dosage form for numerous active pharmaceutical ingredients, among others because they are easy to take, ensure safe dosing and allow cost-effective production on a large scale. This dosage form is also frequently chosen for the administration of viable probiotic microorganisms. Saccharomyces cerevisiae cells granulated in a fluidized bed process, with dicalcium phosphate (DCP), lactose (LAC) and microcrystalline cellulose (MCC) as carrier materials, were tableted using a compaction simulator, varying the compression stress. The tablets were analyzed regarding physical properties, e.g., porosity and tensile strength, as well as microbial survival. Carrier material and compression stress showed a significant influence on survival rate and physical tablet properties. The dependencies were related to material specific deformation characteristics and linked to mechanistic approaches to explain the different sensitivities.

Effect of Process Parameters, Protectants and Carrier Materials on the Survival of Yeast Cells during Fluidized Bed Granulation for Tableting

The administration of living microorganisms is of special interest, with regard to probiotic microorganisms providing health benefits to the patient. Effective dosage forms require the preservation of microbial viability until administration. Storage stability can be improved by drying, and the tablet is an especially attractive final solid dosage form due to its ease of administration and its good patient compliance. In this study, drying of the yeast Saccharomyces cerevisiae via fluidized bed spray granulation is investigated, as the probiotic Saccharomyces boulardii is a variety of it. Fluidized bed granulation enables faster drying than lyophilization on the one hand and lower temperatures than spray drying on the other hand, which are the two predominantly used techniques for life-sustaining drying of microorganisms. Yeast cell suspensions enriched with protective additives were sprayed onto the carrier particles of common tableting excipients, namely, dicalcium phosphate (DCP), lactose (LAC) and microcrystalline cellulose (MCC). Different protectants, such as mono-, di-, oligo- and polysaccharides, but also skimmed milk powder and one alditol, were tested; as they themselves, or chemically similar molecules, are known from other drying technologies to stabilize biological structures such as cell membranes, and thus, improve survival during dehydration. With the combined use of trehalose and skimmed milk powder, survival rates were 300 times higher than without the use of protective additives. In addition to these formulation aspects, the influence of process parameters such as inlet temperature and spray rate were considered. The granulated products were characterized regarding their particle size distribution, moisture content and the viability of the yeast cells. It has been shown that thermal stress on the microorganisms is especially critical, which can be reduced, for example, by reducing the inlet temperature or increasing the spray rate; however, formulation parameters such as cell concentration also influenced survival. The results were used to specify the influencing factors on the survival of microorganisms during fluidized bed granulation and to derive their linkages. Granules based on the three different carrier materials were tableted and the survival of the microorganisms was evaluated and linked to the tablet tensile strength achieved. Using LAC enabled the highest survival of the microorganisms throughout the considered process chain.

Insights on the Critical Parameters Affecting the Probiotic Viability During Stabilization Process and Formulation Development

Probiotics have gained a lot of interest in recent years as an alternative as well as adjuvant therapy for several conditions owing to their health benefits. These live microorganisms have proven efficacy for treating gut disorders, inflammation, bacterial vaginosis, hepatic and depressive disorders, and many more. There are conventional as well as non-conventional formulations available for the delivery of probiotics with the latter having fewer regulatory guidelines. The conventional formulations include the pharmaceutical formulations specifically designed to deliver an efficacious number of viable microorganisms. Studies have indicated 10⁸-10⁹ CFU/g as an ideal dose of probiotics for achieving health benefits, and hence, all the formulations must at least contain the said number of viable bacteria to show a therapeutic effect. The most crucial feature of probiotic formulations is that the bacteria are prone to several environmental and processing factors which all together reduce the viability of the bacteria in the final formulation. These factors include processing parameters like temperature, humidity, pressure, and storage conditions. Thus, the present review primarily focuses on the critical process parameters affecting the probiotic viability during stabilization process and formulation development. Understanding these factors prior to processing helps in delivering probiotics in the required therapeutic numbers at the target site.

Strain-specific differences in behaviour among Lacticaseibacillus rhamnosus cell wall mutants during direct compression

The human body harbours a large variety of microbial communities. It is already well-known that these communities play an important role in human health. Therefore, microbial imbalances can be responsible for several health disorders by different mechanisms. In recent years, probiotic bacteria have been increasingly applied to restore imbalances and stimulate microbiome functions such as immune modulation. Tablets are the dosage form of choice for oral probiotics. Nevertheless, a probiotic tablet with a sufficient amount of viable cells remains a challenge due to the stress of the compression process. Recent research demonstrated that the applied pressure and tableting properties play an important role in the survival of Lacticaseibacillus rhamnosus GG during direct compression. This study focused on the importance of the cell surface molecules in the protection of this prototype probiotic strain during direct compression. Spray-dried powders of L. rhamnosus GG and its exopolysaccharide-deficient mutant and lipoteichoic acid mutant were blended with two different filler-binders and compacted at various compression pressures. Under each tableting condition, the survival rate and tableting properties were analysed. The results demonstrated that the cell surface molecules play an important role in the behaviour of L. rhamnosus GG during direct compression. Specifically, the long, galactose-rich exopolysaccharides of L. rhamnosus served a protective shield during tablet production, promoting the survival rate of this probiotic strain. The D-alanylation of the lipoteichoic acids plays also an important role. When the D-alanyl ester content was completely absent, the survival rate was less affected by the tableting properties. Moreover, this research revealed that the sensitivity to the tableting properties is species and strain dependent.

Characteristics of Effervescent Tablets of Lactobacilli Supplemented with Chinese Ginseng (Panax ginseng C.A. Meyer) and Polygonatum sibiricum

Development of probiotic products has always been popular in the food industry. Considering the advantages of effervescent tablets, developing probiotic products in effervescent tablet form was conducted in this study. Besides three Lactobacillus species, whole root powders of two medicine food homology herbs, Chinese ginseng (Panax ginseng C.A. Meyer) and Polygonatum sibiricum, were added to the formulation in equal amounts for multiple health care functions. Using the plate counting method, the viability of lactobacilli was measured. After tabletting, lactobacilli viability in tablets containing the two herbs, L-group (20 mg herbs/tablet), M-group (60 mg herbs/tablet), and H-group (100 mg herbs/tablet) was higher than that in the control (containing no herbs). After tablet disintegration, the survival rate of lactobacilli after gastrointestinal fluids treatment was measured; it was higher for the L-group and the H-group than for the control. After incubation with dissolved tablets for 1 h, the lethal rate of Staphylococcus aureus and Escherichia coli O157:H7 for tablets containing the herbs was lower than that for the control. In the organoleptic assessment test, the L-group and the control were preferred to the M-group and the H-group. During storage at 25 °C for two months, the viability of lactobacilli in tablets containing the herbs was similar to that in the control. In conclusion, the formulation of the L-group has the best characteristics.

Along the Process Chain to Probiotic Tablets: Evaluation of Mechanical Impacts on Microbial Viability

Today, probiotics are predominantly used in liquid or semi-solid functionalized foods, showing a rapid loss of cell viability. Due to the increasing spread of antibiotic resistance, probiotics are promising in pharmaceutical development because of their antimicrobial effects. This increases the formulation requirements, e.g., the need for an enhanced shelf life that is achieved by drying, mainly by lyophilization. For oral administration, the process chain for production of tablets containing microorganisms is of high interest and, thus, was investigated in this study. Lyophilization as an initial process step showed low cell survival of only 12.8%. However, the addition of cryoprotectants enabled survival rates up to 42.9%. Subsequently, the dried cells were gently milled. This powder was tableted directly or after mixing with excipients microcrystalline cellulose, dicalcium phosphate or lactose. Survival rates during tableting varied between 1.4% and 24.1%, depending on the formulation and the applied compaction stress. More detailed analysis of the tablet properties showed advantages of excipients in respect of cell survival and tablet mechanical strength. Maximum overall survival rate along the complete manufacturing process was >5%, enabling doses of 6 × 108 colony forming units per gram (CFU gtotal−1), including cryoprotectants and excipients.

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.

Importance of pressure plasticity during compression of probiotic tablet formulations

The usefulness, the high production rate and the cost effectiveness make tablets the dosage form of choice for oral probiotics. Nevertheless, probiotic bacteria undergo a lot of mechanical stress during tableting which causes damage to their cell wall and membrane and other bio-active components. This can lead to an inactivation of the probiotic bacteria and therefore in a failure of the probiotic therapy. To obtain a tablet with a sufficient amount of viable cells, research on the influence of formulation and process parameters on bacterial survival is essential. This study aimed to decipher tableting properties of the probiotic powder blends that have a major impact on survival rates. The powder blends consisted of the prototype probiotic strain Lactobacillus rhamnosus GG, a filler-binder and a suitable amount of lubricant. They were manufactured by direct compression at different compression pressures and tableting speeds. The tableting properties were analysed in detail by a 3-D modelling technique, which characterized normalized time, pressure and displacement simultaneously. The results of the 3-D modelling demonstrated the significant effect of the pressure plasticity (e) and the angle of rotation (ω) on the viability of L. rhamnosus GG during direct compression.

Development of bio-yoghurt chewable tablet: a review

Purpose

This paper aims to discuss the limitations surrounding the yoghurt industry and challenges to producing a bio-yoghurt tablet. The paper looks into challenge facing the yoghurt industry, such as manufacturing and distribution, its short shelf life, heat-sensitivity and relatively heavy weight. It further looks into the selection of strains, excipients and storage conditions with special consideration towards maintaining the viability of the probiotics inside bio-yoghurt tablets. The paper also discusses yoghurt standards and definitions across various countries and suggests a more uniform standard be embraced across countries for ease of categorization and production.

Design/methodology/approach

The paper is divided into a few major sections; each exploring various aspects of the yoghurt industry. Topics discussed include challenges in yoghurt production and storage; processes involved in bio-yoghurt tablet production, e.g. maximising viability, choice of excipients and more; market trends of yoghurt consumption and potential; and various food standards in countries around the world with a focus on yoghurt.

Findings

The review finds that yoghurt is a segment of the food industry with big growth potential. Most of the problems associated with yoghurt, i.e. poor shelf life, and heavy weight, can be circumvented by transforming it into a bio-yoghurt tablet. The paper further identifies food standard variations among different countries around the world which could impede yoghurt manufacture and acceptance.

Originality/value

This paper looks the various challenges surrounding the increased uptake of yoghurt, specifically in the Asian markets and suggests a viable option to overcome this problem, i.e. the use of a bio-yoghurt tablet. Should the worldwide bodies come together and agree to a universal standard involving yoghurt, the industry may see an even bigger expansion.

Challenges and approaches for production of a healthy and functional mayonnaise sauce

Mayonnaise is a semisolid oil-in-water (O/W) emulsion which is made through the careful blending of oil, vinegar, egg yolk, and spices (especially mustard). In addition, mayonnaise traditionally contains 70%-80% oil, and egg yolk is a key ingredient contributing to its stability. Despite concerns about high cholesterol level in egg yolk, it is yet the most widely utilized emulsifying agent owing to its high emulsifying capacity. Today, the public knowledge about diet and health has been incremented, compelling the people to consume foodstuffs containing functional features. Thus, consumers, aware of the considerable influence of the diet on their health, demand nutritious and healthier food. Mayonnaise is usually cited by health-related issues due to its high cholesterol and fat content. Many researchers have tried to replace fat, as well as egg yolk completely or partially; however, low-fat mayonnaises require extra ingredients to keep the stability. In other words, each ingredient plays a specific role in textural and oxidative stability, and using alternative emulsifiers and fat replacers may affect the sensorial, textural, and antioxidant features of mayonnaise. Furthermore, mayonnaise, like other high-fat foodstuffs, is vulnerable to auto-oxidation. In addition to using fat replacers, mayonnaise is accompanied with bioactive ingredients to produce a healthy system. Therefore in this review, we gathered a quick summary of the ideas, including lowering the cholesterol and fat and using natural antioxidants, prebiotics, and probiotics in order to produce a healthy and functional mayonnaise sauce.

Elastic recovery of filler-binders to safeguard viability of Lactobacillus rhamnosus GG during direct compression

Tablets are increasingly explored as dosage form for oral probiotics, especially for applications such as pharyngitis and dental health. In such tablets, the dry form increases the stability and the shelf life of the product. In addition, the probiotic cells are entrapped in the tablet matrix, which protects them against the environmental factors in the human body. However, the development of a probiotic tablet with an adequate number of viable cells remains a challenge due to the stress of the compression process. The adverse conditions during production can damage the cells, which leads to a loss of viability and a failure of the therapy. This study aimed to investigate the effect of the compression behavior of filler-binders on the survival of Lactobacillus rhamnosus GG during tablet production. The probiotic tablets were manufactured by direct compression of a freeze-dried mixture of the model L. rhamnosus GG, a filler-binder and a suitable amount of lubricant. The compression behavior was determined by analyzing Heckel and force-displacement plots. The results demonstrated that the elastic recovery of the filler-binder during decompression played a protective role in bacterial survival, reducing the compression stress during manufacturing. Consequently, the bacterial cells were less damaged, which resulted in a higher survival rate and a better stability during long-term storage. In conclusion, the elastic recovery of a filler-binder showed to be an important key in safeguarding probiotic cells during direct compression and storage.

Egg Yolk Extracts as Potential Liposomes Shell Material: Composition Compared with Vesicles Characteristics

Our aim was to propose simple extraction process to obtain phospholipids along with yolk-derived vitamins and fats. Five extracts marked as ethanol/acetone, methanol-chloroform/acetone, hot ethanol, hexane, and cold ethanol were developed and compared. Extracts' compositions were analyzed in terms of phospholipid, polar and nonpolar fraction, cholesterol, carotenoids, and tocopherols content. Further, liposomes prepared from extracts were characterized. The highest extraction efficiency was achieved by a one-step hexane procedure. However, that sample, in contrast to the other four extracts, revealed distinctively lower permeability when used for liposomes membrane formation. Principal component analysis proved that major components contents were decisive for liposomes membranes permeability, whereas minor constituents' content controlled zeta potential and Z-average size.

PRACTICAL APPLICATION

Liposomes are nanocarriers widely used in pharmaceutical industry. Due to intravenous route of administration, they have to be produced from phospholipids of very fine purity. On the other hand, there is increasing interest in nanoencapsulation of labile, bioactive substances for manufacturing of health promoting food. Unfortunately, high-price pure phospholipids are prohibitive for food applications. The use of raw material obtained by simple extraction procedure instead of highly purified phospholipids could be an attractive alternative for food industry.

Optimized tableting for extremely oxygen-sensitive probiotics using direct compression

Faecalibacterium prausnitzii was previously recognized for its intestinal anti-inflammatory activities and it has been shown less abundant in patients with chronic intestinal diseases. However, the main problems encountered in the use of this interesting anaerobic microorganism are firstly its high sensitivity to the oxygen and secondly, its ability to reach the large intestine alive as targeted site. The aim of this study was to investigate the effect of direct compression on the viability of this probiotic strain after different compression pressure and storage using three different excipients (MCC, HPMC and HPMCP). The effect of compression process on cell viability was studied and a strategy was proposed to improve probiotic viability. Results showed that cell viability decreased almost linearly with compression pressure. MCC and HPMC seemed the most favorable carriers and after storage, each tablet exhibited a survival above10⁸ CFU. Storage stability was obtained with a pressure of 201 MPa after 28 days at 25 °C, in anaerobic condition and with 11% relative humidity. Compression after a pre-consolidated stage improved clearly the survival rate due to lower temperature increase and lower shearing force. Thus, direct compression seems to be suitable in producing probiotics tablets with extremely oxygen-sensitive strains, and could provide sufficient protection during storage to expect therapeutic efficiency.

Microbial Stability of Pharmaceutical and Cosmetic Products

This review gives a brief overview about microbial contamination in pharmaceutical products. We discuss the distribution and potential sources of microorganisms in different areas, ranging from manufacturing sites, pharmacy stores, hospitals, to the post-market phase. We also discuss the factors that affect microbial contamination in popular dosage forms (e.g., tablets, sterile products, cosmetics). When these products are contaminated, the microorganisms can cause changes. The effects range from mild changes (e.g., discoloration, texture alteration) to severe effects (e.g., changes in activities, toxicity). The most common method for countering microbial contamination is the use of preservatives. We review some frequently used preservatives, and we describe the mechanisms by which microorganisms develop resistance to these preservatives. Finally, because preservatives are inherently toxic, we review the efforts of researchers to utilize water activity and other non-preservative approaches to combat microbial contamination.

Probiotics production and alternative encapsulation methodologies to improve their viabilities under adverse environmental conditions

Probiotic products are dietary supplements containing live microorganisms producing beneficial health effects on the host by improving intestinal balance and nutrient absorption. Among probiotic microorganisms, those classified as lactic acid bacteria are of major importance to the food and feed industries. Probiotic cells can be produced using alternative carbon and nitrogen sources, such as agroindustrial residues, at the same time contributing to reduce process costs. On the other hand, the survival of probiotic cells in formulated food products, as well as in the host gut, is an essential nutritional aspect concerning health benefits. Therefore, several cell microencapsulation techniques have been investigated as a way to improve cell viability and survival under adverse environmental conditions, such as the gastrointestinal milieu of hosts. In this review, different aspects of probiotic cells and technologies of their related products are discussed, including formulation of culture media, and aspects of cell microencapsulation techniques required to improve their survival in the host.

Technology and potential applications of probiotic encapsulation in fermented milk products

Fermented milk products containing probiotics and prebiotics can be used in management, prevention and treatment of some important diseases (e.g., intestinal- and immune-associated diseases). Microencapsulation has been used as an efficient method for improving the viability of probiotics in fermented milks and gastrointestinal tract. Microencapsulation of probiotic bacterial cells provides shelter against adverse conditions during processing, storage and gastrointestinal passage. Important challenges in the field include survival of probiotics during microencapsulation, stability of microencapsulated probiotics in fermented milks, sensory quality of fermented milks with microencapsulated probiotics, and efficacy of microencapsulation to deliver probiotics and their controlled or targeted release in the gastrointestinal tract. This study reviews the current knowledge, and the future prospects and challenges of microencapsulation of probiotics used in fermented milk products. In addition, the influence of microencapsulation on probiotics viability and survival is reviewed.

Mechanistic approach to stability studies as a tool for the optimization and development of new products based on L. rhamnosus Lcr35® in compliance with current regulations

Probiotics are of great current interest in the pharmaceutical industry because of their multiple effects on human health. To beneficially affect the host, an adequate dosage of the probiotic bacteria in the product must be guaranteed from the time of manufacturing to expiration date. Stability test guidelines as laid down by the ICH-Q1A stipulate a minimum testing period of 12 months. The challenge for producers is to reduce this time. In this paper, a mechanistic approach using the Arrhenius model is proposed to predict stability. Applied for the first time to laboratory and industrial probiotic powders, the model was able to provide a reliable mathematical representation of the effects of temperature on bacterial death (R²>0.9). The destruction rate (k) was determined according to the manufacturing process, strain and storage conditions. The marketed product demonstrated a better stability (k = 0.08 months⁻¹) than the laboratory sample (k = 0.80 months⁻¹). With industrial batches, k obtained at 6 months of studies was comparable to that obtained at 12 months, evidence of the model’s robustness. In addition, predicted values at 12 months were greatly similar (±30%) to those obtained by real-time assessing the model’s reliability. This method could be an interesting approach to predict the probiotic stability and could reduce to 6 months the length of stability studies as against 12 (ICH guideline) or 24 months (expiration date).

Development of probiotic tablets using microparticles: viability studies and stability studies

Alternative vectors to deliver viable cells of probiotics, to those conferring limited resistance to gastrointestinal conditions, still need to be sought. Therefore the main goal of the study was to develop tablets able to protect entrapped probiotic bacteria from gastric acidity, thus providing an easily manufacturing scale-up dosage form to deliver probiotics to the vicinity of the human colon. Whey protein concentrate microparticles with Lactobacillus paracasei L26 were produced by spray-drying and incorporated in tablets with cellulose acetate phthalate and sodium croscarmellose. The viability of L. paracasei L.26 throughout tableting as well as its gastric resistance and release from the tablets were evaluated. Storage stability of L. paracasei L26 tablets was also performed by evaluation of viable cells throughout 60 days at 23°C and 33% relative humidity. A decrease of approximately one logarithmic cycle was observed after the acid stage and the release of L. paracasei L26 from the tablets occurred only after 4 h in the conditions tested. Microencapsulated L. paracasei L26 in tablets revealed some susceptibility to the storage conditions tested since the number of viable cells decreased 2 log cycles after 60 days of storage. However, the viability of L. paracasei L26 after 45 days of storage did not reveal significant susceptibility upon exposure to simulated gastrointestinal conditions. The developed probiotic tablets revealed to be potential vectors for delivering viable cells of L. paracasei L26 and probably other probiotics to persons/patients who might benefit from probiotic therapy.

Stabilization and Target Delivery of Nattokinase Using Compression Coating

The aim of the work is to develop a new formulation in order to stabilize a nutraceutical enzyme Nattokinase (NKCP) in powders and to control its release rate when it passes through the gastrointestinal tract of human. NKCP powders were first compacted into a tablet, which was then coated with a mixture of an enteric material Eudragit L100-55 (EL100-55) and Hydroxypropylcellulose (HPC) by direct compression. The activity of the enzyme was determined using amidolytic assay and its release rates in artificial gastric juice and an intestinal fluid were quantified using bicinchoninic acid assay. Results have shown that the activity of NKCP was pressure independent and the coated tablets protected NKCP from being denatured in the gastric juice, and realized its controlled release to the intestine based on in vitro experiments.

Microencapsulation of bacteriophage felix O1 into chitosan-alginate microspheres for oral delivery

This paper reports the development of microencapsulated bacteriophage Felix O1 for oral delivery using a chitosan-alginate-CaCl(2) system. In vitro studies were used to determine the effects of simulated gastric fluid (SGF) and bile salts on the viability of free and encapsulated phage. Free phage Felix O1 was found to be extremely sensitive to acidic environments and was not detectable after a 5-min exposure to pHs below 3.7. In contrast, the number of microencapsulated phage decreased by 0.67 log units only, even at pH 2.4, for the same period of incubation. The viable count of microencapsulated phage decreased only 2.58 log units during a 1-h exposure to SGF with pepsin at pH 2.4. After 3 h of incubation in 1 and 2% bile solutions, the free phage count decreased by 1.29 and 1.67 log units, respectively, while the viability of encapsulated phage was fully maintained. Encapsulated phage was completely released from the microspheres upon exposure to simulated intestinal fluid (pH 6.8) within 6 h. The encapsulated phage in wet microspheres retained full viability when stored at 4 degrees C for the duration of the testing period (6 weeks). With the use of trehalose as a stabilizing agent, the microencapsulated phage in dried form had a 12.6% survival rate after storage for 6 weeks. The current encapsulation technique enables a large proportion of bacteriophage Felix O1 to remain bioactive in a simulated gastrointestinal tract environment, which indicates that these microspheres may facilitate delivery of therapeutic phage to the gut.