Nasal absorption enhancement of protein drugs independent to their chemical properties in the presence of hyaluronic acid modified with tetraglycine-L-octaarginine

Validation of the Absorption-Enhancing Ability of Oligoarginines Grafted onto a Backbone of Hyaluronic Acid through Animal Studies from Rodents to Primates

The purpose of our research is to develop functional additives that enhance mucosal absorption of biologics, such as peptide/protein and antibody drugs, to provide their non-to-poor invasive dosage forms self-managed by patients. Our previous in vivo and in vitro studies demonstrated that the intranasal absorption of biologics in mice was significantly improved when coadministered with oligoarginines anchored chemically to hyaluronic acid via a glycine spacer, presumably through syndecan-4-mediated macropinocytosis under activation by oligoarginines. The present mouse experiments first revealed that diglycine-L-tetraarginine-linked hyaluronic acid significantly enhanced the intranasal absorption of sulpiride, which is a poor-absorptive organic compound with a low molecular weight. However, similar enhancement was not observed for levofloxacin, which has a similarly low molecular weight but is a well-absorptive organic compound, probably because its absorption was mostly dominated by passive diffusion. The subsequent monkey experiments revealed that there was no species difference in the absorption-enhancing ability of diglycine-L-tetraarginine-linked hyaluronic acid for not only organic compounds but also biologics. This was presumably because the expression levels of endocytosis-associated membrane proteins on the nasal mucosa in monkeys were almost equivalent to those in mice, and poorly membrane-permeable/membrane-impermeable drugs were mainly absorbed via syndecan-4-mediated macropinocytosis, regardless of animal species. Drug concentrations in the brain assessed in mice and monkeys and those in the cerebral spinal fluids (CSFs) assessed in monkeys indicated that drugs would be delivered from the systemic circulation to the central nervous system by crossing the blood-brain and the blood-CSF barriers under coadministration with the hyaluronic acid derivative. In line with our original hypothesis, this new set of data supported that our oligoarginine-linked hyaluronic acid would locally perform on the mucosal surface and enhance the membrane permeation of drugs under its colocalization.

Absorption enhancer approach for protein delivery by various routes of administration: a rapid review

As bioactive molecules, peptides and proteins are essential in living organisms, including animals and humans. Defects in their function lead to various diseases in humans. Therefore, the use of proteins in treating multiple diseases, such as cancers and hepatitis, is increasing. There are different routes to administer proteins, which have limitations due to their large and hydrophilic structure. Another limitation is the presence of biological and lipophilic membranes that do not allow proteins to pass quickly. There are different strategies to increase the absorption of proteins from these biological membranes. One of these strategies is to use compounds as absorption enhancers. Absorption enhancers are compounds such as surfactants, phospholipids and cyclodextrins that increase protein passage through the biological membrane and their absorption by different mechanisms. This review focuses on using other absorption enhancers and their mechanism in protein administration routes.

Mucosal absorption of antibody drugs enhanced by cell-penetrating peptides anchored to a platform of polysaccharides

Our previous studies demonstrated that L-octaarginine grafted onto hyaluronic acid via a tetraglycine spacer significantly enhanced intranasal absorption of protein drugs with a molecular weight (Mw) of 22 kDa or less. The present study focused on its potential as an absorption enhancer for antibody drugs with a larger Mw and the enhancement mechanism. When ranibizumab (48 kDa) alone was intranasally administered in mice, its absolute bioavailability was 0.67% on average. The mean bioavailability elevated to 6.2% under coadministration with tetraglycine-L-octaarginine-linked hyaluronic acid. A similar result was observed under substitution of ranibizumab with certolizumab pegol (91 kDa), although bioavailability itself decreased with the Mw increase, irrespective of coadministration with the hyaluronic acid derivative. Rat experiments also revealed that coadministration with the polysaccharide derivative resulted in significant enhancement of intranasal absorption of trastuzumab (148 kDa). In vitro studies using gene-knocked down cells indicated that syndecan-4-induced macropinocytosis played a crucial role on acceleration of antibody uptake into epithelial cells on the nasal mucosa, irrespective of their Mw. It appeared that neither clathrin heavy chain nor caveolin-1 involved in cellular uptake of antibodies. Tetraglycine-L-octaarginine-linked hyaluronic acid was concluded to be a promising delivery tool that possessed universal absorption-enhancing abilities independent to Mw of biologics.

Development of Vinpocetine-Loaded Nasal Polymeric Micelles via Nano-Spray-Drying

In this present formulation study, vinpocetine-loaded nano-spray-dried polymeric micelles were developed via nano-spray-drying. Three different mucoadhesive excipients were applied in the studies, namely chitosan, hyaluronic acid and hydroxypropyl methylcellulose. In all cases, the formulations had a proper particle size and drug content after drying with spherical morphology and amorphous structure. After rapid dissolution in water, the polymeric micelles had a particle size around 100-130 nm, in monodisperse size distribution. The high encapsulation efficiency (>80%) and high solubilization (approx. 300-fold increase in thermodynamic solubility) contributed to rapid drug release (>80% in the first 15 min) and fast passive diffusion at simulated nasal conditions. The formulated prototype preparations fulfilled the demands of a low-viscosity, moderately mucoadhesive nasal drug delivery system, which may be capable of increasing the overall bioavailability of drugs administered via the auspicious nasal drug delivery route.

Current Understanding of Sodium N-(8-[2-Hydroxylbenzoyl] Amino) Caprylate (SNAC) as an Absorption Enhancer: The Oral Semaglutide Experience

Oral administration of peptide therapeutics faces challenges because of the distinct environment of the gastrointestinal tract. An oral formulation of semaglutide, a glucagon-like peptide 1 receptor agonist, was approved by the U.S. Food and Drug Administration in 2019 as a peptide therapy for the treatment of type 2 diabetes. Oral semaglutide uses sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC) technology to enhance the absorption of semaglutide in the stomach and protect it from degradation by gastric enzymes. This article presents a summary of studies investigating SNAC technology as an absorption enhancer for a number of molecules and, in particular, explores how SNAC, once coformulated with oral semaglutide, facilitates increased absorption and bioavailability. Practical advice and dispensing information for pharmacists is also provided.

Performance of Cell-Penetrating Peptides Anchored to Polysaccharide Platforms Applied via Various Mucosal Routes as an Absorption Enhancer

We have been investigating the potential of cell-penetrating peptides anchored to polymeric platforms as a novel absorption enhancer which delivers biologics into systemic circulation via mucosal routes. Our previous mouse experiments demonstrated that hyaluronic acid modified with l-octaarginine, a typical cell-penetrating peptide, via a tetraglycine spacer significantly enhanced the mucosal absorption of protein drugs applied into the nasal cavities, irrespective of the molecular weights (M_w) of the drugs. The present study evaluated the performance of tetraglycine-l-octaarginine-linked hyaluronic acid applied via various mucosal routes. Somatropin (M_w: ca. 22.1 kDa) was moderately absorbed from the lung mucosa, and the mean absolute bioavailability (BA) reached 19% under enhancer-free conditions; nevertheless, its BA under intranasal administration was approximately 1% or less. Its BA significantly elevated to 46% on average through intrapulmonary coadministration with tetraglycine-l-octaarginine-linked hyaluronic acid. When the administration site was replaced with the oral cavities, an extreme reduction in somatropin absorption was observed with a mean BA of 0.056% under enhancer-free conditions. Intraoral coadministration with tetraglycine-l-octaarginine-linked hyaluronic acid resulted in a 6.3-fold elevation of somatropin absorption with statistical significance. A similar enhancement was observed under intrarectal administration with a further reduction in BA. On the other hand, the hyaluronic acid derivative did not exhibit the absorption-enhancing ability under intragastric administration, probably due to the lack of stabilization effects against enzyme-susceptible biologics. The results indicated that the intrapulmonary route was suitable for maximizing the mucosal absorption of biologics, and that there was a likelihood of the intraoral route with user convenience. When somatropin was substituted with fluorescein isothiocyanate-conjugated dextran with an average M_w range of 4-70 kDa, similar phenomena were observed under intrapulmonary and intranasal administration. BA decreased with an increase in the M_w of dextran; however, the ratio of BA under enhancer-present conditions to that under enhancer-free conditions was consistently around 3, indicating that the performance of the hyaluronic acid derivative was M_w-independent, irrespective of the administration route.

The nanotechnological approach for nasal delivery of peptide drugs: a comprehensive review

This review gathers recent studies, patents, and clinical trials involving the nasal administration of peptide drugs to supply a panorama of developing nanomedicine advances in this field. Peptide drugs have been featured in the pharmaceutical market, due to their high efficacy, biological activity, and low immunogenicity. Pharmaceutical industries need technology to circumvent issues relating to peptide stability and bioavailability. The oral route offers very harsh and unfavourable conditions for peptide administration, while the parenteral route is inconvenient and risky for patients. Nasal administration is an attractive alternative, mainly when associated with nanotechnological approaches. Nanomedicines may improve the nasal administration of peptide drugs by providing protection for the macromolecules from enzymes while also increasing their time of retention and permeability in the nasal mucosa. Nanomedicines for nasal administration containing peptide drugs have been acclaimed for both prevention, and treatment, of infections, including the pandemic COVID-19, cancers, metabolic and neurodegenerative diseases.

Kinetic control of Phytic acid/Lixisenatide/Fe (III) ternary nanoparticles assembly process for sustained peptide release

The preferable choice of sustained peptide delivery systems is generally polymer-based microspheres in which their large particle size, wide size distribution, low drug encapsulation efficacy, poor colloidal stability, and undesirable burst release eventually hinder their clinical translation. In this study, a nanoscale ternary Lixisenatide (Lix) sustained delivery system based on strong multivalent interactions (electrostatic and coordination complexation) among small molecular phytic acid (PA), Lix and Fe³⁺ was developed. Flash nanocomplexation (FNC) was utilized to facilitate the rapid and efficient mixing of the three components and kinetically control the assembly process that enabled dynamic balance of two competitive chemical reactions with different kinetic rates (slow chemical reaction of PA/Lix and fast chemical reaction of PA/Fe³⁺) to generate structural uniform ternary nanoparticles and avoid heterogeneous complexes. By tuning the mixing conditions (i.e., flow rate, mass ratio, concentration, pH value, etc.), the ternary PA/Lix/Fe³⁺ nanoparticles were assembled with reproducible production in a manner of high uniformity and scalability, achieving small size (∼50 nm), uniform composition (PDI: ∼0.12), favourable colloidal stability, high encapsulation efficiency (∼100%), and tunable drug release kinetics. The optimized formulation exhibited a minor Lix release (<20%) in the first day and extended peptide release period over 8 days. Unexpectedly, upon a single injection administration, the as-prepared formulation (600 μg/kg) rapidly brought the high BGL (∼30 mmol/L) back to normal range (<10 mmol/L) within the initial 6 h and achieved a 180 h glycemic control in T2D mouse model. Moreover, this sustained peptide delivery system demonstrated a repeatable hypoglycemic effects and significantly suppressed the pathological damage of major organs following multiple injection. This sustained peptide delivery system with aqueous, facile and reproducible preparation process possesses good biocompatibility, tunable release kinetics, and prolonged hypoglycemic effects, portending its great translational potential in the chronic disease treatment.