Physicochemical Investigation of Engineered Nanosuspensions Containing Model Drug, Lansoprazole

Cyclodextrin-Based Arsenal for Anti-Cancer Treatments

Anti-cancer drugs are mostly limited in their use due to poor physicochemical and biopharmaceutical properties. Their lower solubility is the most common hurdle limiting their use upto their potential. In the recent years, the cyclodextrin (CD) complexation have emerged as existing approach to overcome the problem of poor solubility. CD-based nano-technological approaches are safe, stable and showed well in vivo tolerance and greater payload for encapsulation of hydrophobic drugs for the targeted delivery. They are generally chosen due to their ability to get self-assembled to form liposomes, nanoparticles, micelles and nano-sponges etc. This review paper describes a birds-eye view of the various CD-based nano-technological approaches applied for the delivery of anti-cancer moieties to the desired target such as CD based liposomes, niosomes, niosoponges, micelles, nanoparticles, monoclonal antibody, magnetic nanoparticles, small interfering RNA, nanorods, miscellaneous formulation of anti-cancer drugs containing CD. Moreover, the author also summarizes the various shortcomings of such a system and their way ahead.

Drug-Encapsulated Cyclodextrin Nanosponges

To date, a number of nanocarriers, either inorganic or organic, have been developed to improve the delivery and therapeutic efficacy of various drugs. Drug delivery systems have attempted to overcome the undesirable pharmacokinetic problems encountered. Among the various nanomaterials that have been designed as potential nanocarriers, cyclodextrin-based polymers are of particular interest in this review.Cyclodextrins (CD) are a class of cyclic glucopyranose oligomers, obtained from starch by enzymatic action, with a characteristic toroidal shape that forms a truncated cone-shaped lipophilic cavity. The main common native cyclodextrins are named α, β, and γ which comprise six, seven, and eight glucopyranose units, respectively. Cyclodextrins have the capability to include compounds whose size and polarity are compatible with those of their cavity.Cyclodextrin-based cross-linked polymers, often referred to as "cyclodextrin nanosponges" (CDNSs), attract great attention from researchers for solving major bioavailability problems such as inadequate solubility, poor dissolution rate, and limited stability of some agents, as well as increasing their effectiveness and decreasing unwanted side effects.Registered patents about this novel system in various fields, different pharmaceutical applications, and classes of drugs encapsulated by CDNSs are detailed. The features outlined make CDNSs a promising platform for the development of innovative and advanced delivery systems.

Biomedical Application of Cyclodextrin Polymers Cross-Linked via Dianhydrides of Carboxylic Acids

Cyclodextrin-based nanosponges (CD-NS) are a novel class of polymers cross-linked with a three-dimensional network and can be obtained from cyclodextrins (CD) and pyromellitic dianhydride. Their properties, such as their ability to form an inclusion complex with drugs, can be used in biomedical science, as nanosponges influence stability, toxicity, selectivity, and controlled release. Most pharmaceutical research use CD-NS for the delivery of drugs in cancer treatment. Application of molecular targeting techniques result in increased selectivity of CD-NS; for example, the addition of disulfide bridges to the polymer structure makes the nanosponge sensitive to the presence of glutathione, as it can reduce such disulfide bonds to thiol moieties. Other delivery applications include dermal transport of pain killers or photosensitizers and delivery of oxygen to heart cells. This gives rise to the opportunity to transition to medical scaffolds, but more, in modern times, to create an ultrasensitive biosensor, which employs the techniques of surface-modified nanoparticles and molecularly imprinted polymers (MIP). The following review focuses on the biomedical research of cyclodextrin polymers cross-linked via dianhydrides of carboxylic acids.

Nanosponges as protein delivery systems: Insulin, a case study

Cyclodextrin-based nanosponges have been found to bepromising drug delivery systems. This paper investigates an application that still needs to be studied in depth, that is, the oral delivery of peptides and proteins, choosing insulin as a case study. The nanospongewas synthesized by crosslinkingβ-cyclodextrins withpyromellitic dianhydride, adopting a top-down approach for its subsequent formulation. Aphysicochemical characterization, in-vitro andin-vivo tests were carried out on the formulation developed. It was nanometric (around 250 nm) with high negative zeta potential, mucoadhesion and swelling properties, good loading capability (about 14%) and encapsulation efficiency (above 90%). The in-vitro release of insulin was negligible at a gastric pH (below 2%) while sustained at an intestinal pH, thus showing a pH-sensitive behaviour of the nanosponge. The Caco-2 cell permeability assay proved that the intestinal permeation of insulin was enhanced when loaded inside the nanosponge. The in-vivo studies confirmed the presence of insulin in rat plasma and a marked hypoglycemic effect in diabetic mice after duodenal and oral administrations, respectively. These preliminary results are encouraging with a view to continuing to study this β-cyclodextrin nanosponge technology for the oral administration of insulin and extending this approach to other proteins of pharmaceutical interest.

History of Cyclodextrin Nanosponges

Nowadays, research in the field of nanotechnology and nanomedicine has become increasingly predominant, focusing on the manipulation and development of materials on a nanometer scale. Polysaccharides have often been used as they are safe, non-toxic, hydrophilic, biodegradable and are low cost. Among them, starch derivatives and, in particular, cyclodextrin-based nanosponges (CD NSs) have recently emerged due to the outstanding properties attributable to their peculiar structure. In fact, alongside the common polysaccharide features, such as the presence of tunable functional groups and their ability to interact with biological tissues, thus giving rise to bioadhesion, which is particularly useful in drug delivery, what makes CD NSs unique is their three-dimensional network made up of crosslinked cyclodextrin units. The name “nanosponge” appeared for the first time in the 1990s due to their nanoporous, sponge-like structure and responded to the need to overcome the limitations of native cyclodextrins (CDs), particularly their water solubility and inability to encapsulate charged and large molecules efficiently. Since CD NSs were introduced, efforts have been made over the years to understand their mechanism of action and their capability to host molecules with low or high molecular weight, charged, hydrophobic or hydrophilic by changing the type of cyclodextrin, crosslinker and degree of crosslinking used. They enabled great advances to be made in various fields such as agroscience, pharmaceutical, biomedical and biotechnological sectors, and NS research is far from reaching its conclusion. This review gives an overview of CD NS research, focusing on the origin and key points of the historical development in the last 50 years, progressing from relatively simple crosslinked networks in the 1960s to today’s multifunctional polymers. The approach adopted in writing the present study consisted in exploring the historical evolution of NSs in order to understand their role today, and imagine their future.

22 factorial design-based biocompatible microneedle arrays containing artemether co-loaded with lumefantrine nanoparticles for transepidermal delivery

The present study was intended to enhance the permeation of artemether and lumefantrine by encapsulating in dissolvable microneedle arrays for extended action. Lumefantrine-nanoparticles were synthesized using chitosan mediated gelation and optimized by 2² factorial designs. The particle size, zeta potential and % entrapment efficiency of the optimized nanoparticles F5 were 105 ± 3.64 nm, 24.4 ± 0.54 mV and 83.94 ± 1.71%, respectively. The nanoparticles showed a controlled-release of 79.15 ± 2.45% for lumefantrine after 24 h and stability for 6 months. A combination of biocompatible polymers (PVA and PVP K - 12) was used to develop dissolvable microneedle of artemether co-loaded lumefantrine nanoparticles. The SEM and TEM analysis confirmed the needle-shaped morphology with a size of 672 ± 0.99 μm. The in-vitro release of microneedle showed biphasic release pattern for both artemether and lumefantrine, with an initial burst followed by controlled-release profile. The ex-vivo study of optimized formulation showed 70.94 ± 2.45% and 65.87 ± 1.94% permeation for artemether and lumefantrine, respectively, after 24 h. Thus, microneedle-based delivery provides an alternative to painful intravenous administration and a promising approach to increase the penetration of drugs across the skin barrier. Graphical abstract Fabrication of microneedle arrays of artemether co-loaded with lumefantrine nanoparticles.

A Comprehensive Patent Review on β-cyclodextrin Cross-linked Nanosponges for Multiple Applications

BACKGROUND

Currently, the most important challenge in the development of therapeutics and actives is their poor aqueous solubility and bioavailability.

OBJECTIVE

The low aqueous solubility, poor pharmacokinetic properties, and bioavailability associated with novel actives manifest in numerous challenges in the formulation of conventional dosage forms like tablets, capsules, suspensions, emulsions, etc. Nanosponges are a novel class of drug delivery system capable of encapsulating or entrapping both lipophilic and hydrophilic drugs. Target-specific drug delivery and controlled drug release are the advantages offered by nanosponges which make them a promising anti-tumor drug delivery system.

METHODS

Nanosponges are colloidal structures comprising solid nanoparticles with cavities and meshlike structures for encapsulation of wide varieties of substances like antineoplastic agents, proteins and peptides, volatile oils, genetic material, etc. The methods of preparation of β-cyclodextrin-based nanosponges include solvent evaporation method, emulsion solvent evaporation method, ultrasound-assisted synthesis, hyper cross-linked cyclodextrin and interfacial phenomenon method. A large variety of nanosponges- based formulations are available in the market and some formulations of prostavastin, brexin, glymesason, mena-gargle, etc. are under clinical trials.

RESULTS

Nanosponges possess potential applications in target site-specific drug delivery to liver, spleen, and lungs. Due to the surface functionalization, nanosponges show broad applications in water purification, protein delivery, chemical sensors, detection of explosives, agriculture, etc. In the near future, nanosponges-based products will capture a huge market for commercialization due to their improved properties and advantages.

CONCLUSION

This review provides an account of the patents related to nanosponges (2006-2018) and covers the broad applications of β-cyclodextrin-based nanosponges, their roles in vaccine delivery, cancer therapy, fire engineering, water purification, etc.

SANS investigation of water adsorption in tunable cyclodextrin-based polymeric hydrogels

A quantitative law for the hydration-dependence of pore size in cyclodextrin-based hydrogels is provided by SANS experiments.