Mershen Govender

A review of the advancements in probiotic delivery: Conventional vs. non-conventional formulations for intestinal flora supplementation.

Probiotic delivery systems are widely used nutraceutical products for the supplementation of natural intestinal flora. These delivery systems vary greatly in effectiveness to exert health benefits for a patient. Probiotic delivery systems can be categorized into conventional, pharmaceutical formulations, and non-conventional, mainly commercial food-based, products. The degree of health benefits provided by these probiotic formulations varies in their ability to deliver viable, functional bacteria in large enough numbers (effectiveness), to provide protection against the harsh effects of the gastric environment and intestinal bile (in vivo protection), and to survive formulation processes (viability). This review discusses the effectiveness of these probiotic delivery systems to deliver viable functional bacteria focusing on the ability to protect the encapsulated probiotics during formulation process as well as against harsh physiological conditions through formulation enhancements using coatings and polymer enhancements. A brief overview on the health benefits of probiotics, current formulation, patient and legal issues facing probiotic delivery, and possible recommendations for the enhanced delivery of probiotic bacteria are also provided. Newer advanced in vitro analyses that can accurately determine the effectiveness of a probiotic formulation are also discussed with an ideal probiotic delivery system hypothesized through a combination of the two probiotic delivery systems described.

A review of the chemical modification techniques of starch

Starch is a naturally occurring storage copolymer with unique physicochemical properties. There are, however, some key structural properties of starch that can be modified in order to functionalize the copolymer to meet specific requirements. Specifically, the chemical modification of starch provides a variety of physicochemical benefits, some of which have been used previously to functionalize preformed drug delivery systems. Of the three main chemical modification methods reviewed (namely: oxidation, esterification and etherification), surface chemical oxidation introduces more pertinent physicochemical properties that increase overall drug delivery system efficacy and applicability. Surface oxidation evidently is the more preferable chemical modification method of pre-formed starch particles and has the greatest potential for further development when compared to the other reviewed chemical modification methods. The use of modified starch in clinical trials as well as the potential future implications of these systems is also included in this review.

A gastro-resistant ovalbumin bi-layered mini-tablet-in-tablet system for the delivery of Lactobacillus acidophilus probiotic to simulated human intestinal and colon conditions

The viability of probiotic bacteria during formulation processes and delivery is vital to ensure health benefits. This study focuses on the use of gastro‐resistant denatured ovalbumin for the targeted delivery of probiotic Lactobacillus acidophilus to simulated human intestinal and colon conditions through a bi‐layered mini‐tablet‐in‐tablet system (BMTTS).

A Dual-Biotic System for the Concurrent Delivery of Antibiotics and Probiotics: In Vitro, Ex Vivo, In Vivo and In Silico Evaluation and Correlation

PurposeA delayed release bio-polymeric Dual-Biotic system has been extensively evaluated in this study to overcome the therapeutic issue of probiotic killing due to incorrect administration with the antibiotic.MethodsIn vitro and ex vivo release and characterization studies have been undertaken on the Dual-Biotic system. In vivo analyses utilizing a Large White pig model were also performed with commercial products used as a comparison. Intestinal fluid for probiotic quantification was aspirated using a surgically implanted intestinal cannula with Lactobacillus acidophilus cell counts determined through luminescence and inoculation onto Lactobacilli-specific agar. Plasma amoxicillin concentrations were determined through Ultra-Performance Liquid Chromatography. The reactional profile and crosslinking mechanism of ovalbumin and genipin was elucidated using molecular mechanic energy relationships in a vacuum system by exploring the spatial disposition of different concentrations of genipin with respect to ovalbumin with ovalbumin/genipin ratios of 1:1, 1:5 and 1:10.ResultsIn vivo evaluation of the Dual-Biotic system detailed maximum Lactobacillus viability (~455% baseline viability) 6 h after oral administration. Concurrent administration of the commercial products revealed a 75% decrease in bacterial viability when compared to the controls analyzed. A level A in vitro-in vivo correlation was also established with 96.9% predictability of amoxicillin release ascertained. The computational results achieved corroborated well with the experimental findings and physicochemical data.ConclusionsEvaluation and correlation of the Dual-Biotic system has detailed the success of the formulation for the concurrent delivery of an antibiotic and probiotic.

Drug Delivery Strategies for Antivirals against Hepatitis B Virus

Chronic hepatitis B virus (HBV) infection poses a significant health challenge due to associated morbidity and mortality from cirrhosis and hepatocellular cancer that eventually results in the breakdown of liver functionality. Nanotechnology has the potential to play a pivotal role in reducing viral load levels and drug-resistant HBV through drug targeting, thus reducing the rate of evolution of the disease. Apart from tissue targeting, intracellular delivery of a wide range of drugs is necessary to exert a therapeutic action in the affected organelles. This review encompasses the strategies and techniques that have been utilized to target the HBV-infected nuclei in liver hepatocytes, with a significant look at the new insights and most recent advances in drug carriers and their role in anti-HBV therapy.

Stimuli-responsive polymers as smart drug delivery systems: Classifications based on carrier type and triggered-release mechanism

Abstract Stimuli-responsive or smart polymeric drug delivery is a dynamic research field, involving the use of natural or synthetic polymers that are engineered to exert therapeutic effects in response to physicochemical and physiological processes as well as externally applied stimuli. Often termed as “smart” polymers, “environmental-sensitive” polymers, or “intelligent” polymers, these polymers are unique in that they have the ability to rapidly modify their microstructure to minor environmental changes and revert to their original state once the stimulus is removed. This chapter overviews the use of stimuli-responsive polymers and their successful application in the broad field of drug delivery. The various types of stimulus responses as well as the categories of the subsequently developed responsive materials will be detailed. Examples of the stimuli responses discussed include physiological changes in temperature, pH, and blood plasma constituents as well as externally applied stimuli such as electric current, photo-stimulation, and magnetic fields. Furthermore, these polymers are classified based on their carrier type and subsequent delivery mechanism. Emphasis on recent, more advanced stimuli-responsive systems is further provided with the future potential of these drug delivery techniques highlighted.

3D Printed, PVA–PAA Hydrogel Loaded-Polycaprolactone Scaffold for the Delivery of Hydrophilic In-Situ Formed Sodium Indomethacin

3D printed polycaprolactone (PCL)-blended scaffolds have been designed, prepared, and evaluated in vitro in this study prior to the incorporation of a polyvinyl alcohol–polyacrylic acid (PVA–PAA) hydrogel for the delivery of in situ-formed sodium indomethacin. The prepared PCL–PVA–PAA scaffold is proposed as a potential structural support system for load-bearing tissue damage where inflammation is prevalent. Uniaxial strain testing of the PCL-blended scaffolds were undertaken to determine the scaffold’s resistance to strain in addition to its thermal, structural, and porosimetric properties. The viscoelastic properties of the incorporated PVA–PAA hydrogel has also been determined, as well as the drug release profile of the PCL–PVA–PAA scaffold. Results of these analyses noted the structural strength, thermal stability, and porosimetric properties of the scaffold, as well as the ability of the PCL–PVA–PAA scaffold to deliver sodium indomethacin in simulated physiological conditions of pH and temperature. The results of this study therefore highlight the successful design, fabrication, and in vitro evaluation of a 3D printed polymeric strain-resistant supportive platform for the delivery of sodium indomethacin.

Design and evaluation of an oral multiparticulate system for dual delivery of amoxicillin and Lactobacillus acidophilus

AIM A delayed-release dual delivery system for amoxicillin and the probiotic Lactobacillus acidophilus was developed and evaluated. MATERIALS & METHODS Statistical optimization of a cross-linked denatured ovalbumin protective matrix was first synthesized using a Box-Behnken experimental design prior to encapsulation with glyceryl monostereate. The encapsulated ovalbumin matrix was thereafter incorporated with amoxicillin in a gastro-resistant capsule. In vitro characterization and stability analysis of the ovalbumin and encapsulated components were also performed Results: Protection of L. acidophilus probiotic against the bactericidal effects of amoxicillin within the dual formulation was determined. CONCLUSION The dual formulation in this study proved effective and provides insight into current microbiome research to identify, classify and use functional healthy bacteria to develop novel probiotic delivery technologies.