Alginate-coating of artemisinin-loaded cochleates results in better control over gastro-intestinal release for effective oral delivery

Techniques, applications and prospects of polysaccharide and protein based biopolymer coatings: A review

The growing relevance of sustainable materials has recently led to the exploration of naturally derived biopolymeric hydrogels as coating materials due to their biodegradability, biocompatibility, ease of fabrication and modification. Although many review articles exist on biopolymeric coatings, they mainly focus on a specific polysaccharide, protein biopolymer, or a particular application- biomedical engineering or food preservation. The current review first summarizes the commonly used polysaccharide and protein-based biopolymers like chitosan, alginate, carrageenan, pectin, cellulose, starch, pullulan, agarose and silk fibroin, gelatin, respectively, with a systematic description of the techniques widely used for physical coating on substrates. Then, broad applications of these biopolymeric coatings on various substrates in biomedical engineering- 3D scaffolds, biomedical implants, and nanoparticles are described in detail. It also entails the application of biopolymeric coatings for food preservation in the form of food packaging and edible coatings. A brief discussion on the newly discovered interest in exploring biopolymers for anticorrosive coating applications is also included. Finally, concluding remarks on the role of biopolymer microstructures in forming homogeneous coatings, prospective alternatives to the currently used biopolymers as coating material and the advent of computer-aided technologies to expedite experimental findings are presented.

Phthalocyanine-based glucose-responsive nanocochleates for dynamic prevention of β-cell damage in diabetes

Phthalocyanine is a blue-colored macrocyclic compound with excellent anti-oxidant and lipid-peroxidation abilities due to its intermolecular π-π stacking structure. Antioxidants inhibit intracellular reactive oxygen species formation and decrease oxidation defense ability of the enzymes in diabetes management. The present study aimed to fabricate concanavalin A conjugated phthalocyanine-loaded cochleates (Formulation PhConA) as a glucose-sensitive lipidic system and estimate its efficacy in streptozotocin-induced male Sprague Dawley diabetic rats for 28 days. Thin-film hydration and trapping methods were used in the preparation of liposomes and cochleates, respectively, whereas the surface was modified for concanavalin A conjugation using EDAC: NHS (1:1). Formulation PhConA with rod-shaped structures showed particle size of 415.7 ± 0.46 nm, PdI value of 0.435 ± 0.09, encapsulation efficiency of 85.64 ± 0.34%, and 84.55 ± 0.29% release of phthalocyanine for 56 h. The circular dichroism study displayed a slight deviation after the conjugation effect of concanavalin A to cochleates. The in-vivo studies of the formulation PhConA improved the blood glucose levels along with defensive effect on the liver to overcome the hyperlipidemic effect. The rigid structure of cochleates prolongs the drug elimination from systemic circulation and extends its effect for a longer duration by decreasing the blood glucose level. Thus, the glucose-sensitive formulation PhConA showed significant improvement in diabetic rats within the period of 28 days by improving the oxidative defense and protecting the pancreatic β-cells.

Tailored Drug Delivery Platforms: Stimulus-Responsive Core-Shell Structured Nanocarriers

Core-shell structured nanocarriers have come into the scientific spotlight in recent years due to their intriguing properties and wide applications in materials chemistry, biology, and biomedicine. Tailored core-shell structures to achieve desired performance have emerged as a research frontier in the development of smart drug delivery system. However, systematic reviews on the design and loading/release mechanisms of stimulus-responsive core-shell structured nanocarriers are uncommon. This review starts with the categories of core-shell structured nanocarriers with different means of drug payload, and then highlights the controlled release mechanism realized through stimulus-response processes triggered under different environments. Finally, some multifaceted perspectives on the design of core-shell structured materials as drug carriers are addressed. This work aims to provide new enlightenments and prospects in the drug delivery field for further developing advanced and smart nanocarriers.

Recent advances in cellulose, pectin, carrageenan and alginate-based oral drug delivery systems

Polymers-based drug delivery systems constitute one of the highly explored thrust areas in the field of the medicinal and pharmaceutical industries. In the past years, the properties of polymers have been modified in context to their solubility, release kinetics, targeted action site, absorption, and therapeutic efficacy. Despite the availability of diverse synthetic polymers for the bioavailability enhancement of drugs, the use of natural polymers is still highly recommended due to their easy availability, accessibility, and non-toxicity. The aim of the review is to provide the available literature of the last five years on oral drug delivery systems based on four natural polymers i.e., cellulose, pectin, carrageenan, and alginate in a concise and tabulated manner. In this review, most of the information is in tabulated form to provide easy accessibility to the reader. The data related to active pharmaceutical ingredients and supported components in different formulations of the mentioned polymers have been made available.

Cochleate drug delivery systems: An approach to their characterization

Cochleate systems formed from phospholipids have very useful properties as drug delivery systems with sustained release capabilities, which are able to improve bioavailability and efficacy, reduce toxicity and increase the shelf-life of encapsulated molecules. These nanometric or micrometric structures are usually obtained after interaction of negatively charged liposomes with a positively charged bridging agent. Many different methods are now available to prepare cochleates and there are also numerous techniques that can be used to characterize them, some of which can be easily applied while others require more sophisticated equipment or analysis. The present review describes the important features of this drug delivery system; including their structural properties and potential applications, as well as a brief account of methods for their preparation and an extensive description of the techniques used for their characterization. This information could guide formulators in their choice of methods of characterization that would be best suited to their needs in terms of time, precision and technological difficulty.

Encapsulation of Cochleates Derived from Salmonella Infantis with Biopolymers to Develop a Potential Oral Poultry Vaccine

The aim of this study was to develop and characterize Salmonellaenterica serovar Infantis (S. Infantis) cochleates protected by encapsulation technology as a potential vaccine and to determine its safety in pullets. Cochleates were encapsulated by two technologies, spray drying and ionotropic gelation at different concentrations (0-15% v/v), and were characterized by physicochemical properties, protein content and Fourier Transform Infrared Spectroscopy (FTIR). The cochleates were white liquid suspensions with tubular shapes and a protein content of 1.0-2.1 mg/mL. After encapsulation by spray drying, microparticles ranged in size from 10.4-16.9 µm, were spherical in shape, and the protein content was 0.7-1.8 mg/g. After encapsulation by ionotropic gelation, beads ranged in size from 1620-1950 µm and were spherical in shape with a protein content of 1.0-2.5 mg/g. FTIR analysis indicated that both encapsulation processes were efficient. The cochleates encapsulated by ionotropic gelation were then tested for safety in pullets. No ill effect on the health of animals was observed upon physical or postmortem examination. In conclusion, this study was the first step in developing a potential oral S. Infantis vaccine safe for poultry using a novel cochleate encapsulation technology. Future studies are needed to determine the effectiveness of the vaccine.

Enhanced oral permeability of Trans-Resveratrol using nanocochleates for boosting anticancer efficacy; in-vitro and ex-vivo appraisal

Hepatocellular carcinoma (HCC) is a prevalent liver cancer representing the fourth most lethal cancer worldwide. Trans-Resveratrol (T-R) possesses a promising anticancer activity against HCC. However, it suffers from poor bioavailability because of the low solubility, chemical instability, and hepatic metabolism. Herein, we developed T-R-loaded nanocochleates using a simple trapping method. Nanocarriers were optimized using a comprehensive in-vitro characterization toolset and evaluated for the anticancer activity against HepG2 cell line. T-R-loaded nanocochleates demonstrated monodispersed cylinders (163.27 ± 2.68 nm and 0.25 ± 0.011 PDI) and -46.6 mV ζ-potential. They exhibited a controlled biphasic pattern with minimal burst followed by sustained release for 72 h. Significant enhancements of Caco-2 transport and ex-vivo intestinal permeation over liposomes, with 1.8 and 2.1-folds respectively, were observed. Nanocochleates showed significant reduction of 24 h IC₅₀ values compared to liposomes and free T-R. Moreover, an efficient knockdown of anti-apoptotic (Bcl-2) and cancer stemness (NANOG) genes was demonstrated. To the best of our knowledge, we are the first to develop T-R loaded nanocochleates and scrutinize its potential in suppressing NANOG expression, 2-folds lower, compared to free T-R. According to these auspicious outcomes, nanocochleates represent a promising nanoplatform to enhance T-R oral permeability and augment its anticancer efficacy in the treatment of HCC.

The relationship between mucoadhesive polymers and surface coating in tablets for the controlled colonic delivery of a poorly water-soluble drug

BACKGROUND

The mucoadhesive polymers play an important role in targeted and controlled drug delivery.

OBJECTIVES

This study aimed to investigate the drug release behaviour and interpret the role of mucoadhesive polymers involved in the coating layer of mucoadhesive tablets for the sustained release of a poorly water-soluble drug.

METHODS

A solid dispersion of prednisolone and zein was used in the core tablets created with two mucoadhesive polymers, which included Carbopol 940 and hydroxypropyl methylcellulose K4M. In addition, the properties of a single-layer coating, created from the combination of zein and Kollicoat MAE 100P to delay release through the upper parts of the gastrointestinal tract, were investigated in the presence of the above mucoadhesive polymers; these properties included drug dissolution, mucoadhesion, surface morphology, swelling and erosion.

RESULTS

The mucoadhesive polymer concentrations and types were integrated not only into the core tablets through a swelling/erosion mechanism but also into the surface polymer coatings for controlled drug release. HPMC was preferred in the formulations due to the ability to form pores on the surface coating, allowing water uptake so that the coating could control drug release for a later stage via a swelling/erosion mechanism.

CONCLUSION

The proposed mechanism determined in this project could be beneficial in the selection of polymers for applications targeting the colon with coated mucoadhesive tablets. Graphical abstract.

Continuous, high-throughput production of artemisinin-loaded supramolecular cochleates using simple off-the-shelf flow focusing device

Lipid cochleates are gaining increasing interest as drug-carriers. However, their preparation relies on conventional batch processes that are complex, time consuming and lack batch-to-batch reproducibility; presenting a bottleneck for clinical translation. We report an efficient continuous preparation process for artemisinin-loaded cochleates (ART-cochleates) using inexpensive off-the-shelf flow focusing device. By carefully controlling the flow focusing parameters, we showed along with the mechanism that, ART-cochleates of uniform and tuneable size (~180 nm in width and ~1030 nm in length) were obtained with low dispersity (0.18 in width and 0.27 in length), narrow size distribution and high reproducibility compared to the batch process. The device achieved high throughput of 11.5 g/day with ART encapsulation of 64.24 ± 2.5% and loading of 83.37 ± 3.68 mg ART/g of cochleates. Art-cochleates were non-toxic and showed sustained in-vitro release of ART with effective transepithelial permeability across intestinal Caco-2 monolayer (~60% and ~25% transport for pure ART and ART-cochleates, respectively) resulting in better in-vitro bioavailability. The off-the-shelf device is envisioned to be highly promising platform for continuous and high-throughput manufacturing of drug-loaded cochleates in a controlled and reproducible manner. It has potential to enable clinical translation of drug-loaded cochleates with predicable drug release, absorption and bioavailability.