Synthesis and Properties of Sucrose- and Lactose-Based Aromatic Ester Surfactants as Potential Drugs Permeability Enhancers

Recent Progress in the Oral Delivery of Therapeutic Peptides and Proteins: Overview of Pharmaceutical Strategies to Overcome Absorption Hurdles

Purpose

Proteins and peptides have secured a place as excellent therapeutic moieties on account of their high selectivity and efficacy. However due to oral absorption limitations, current formulations are mostly delivered parenterally. Oral delivery of peptides and proteins (PPs) can be considered the need of the hour due to the immense benefits of this route. This review aims to critically examine and summarize the innovations and mechanisms involved in oral delivery of peptide and protein drugs.

Methods

Comprehensive literature search was undertaken, spanning the early development to the current state of the art, using online search tools (PubMed, Google Scholar, ScienceDirect and Scopus).

Results

Research in oral delivery of proteins and peptides has a rich history and the development of biologics has encouraged additional research effort in recent decades. Enzyme hydrolysis and inadequate permeation into intestinal mucosa are the major causes that result in limited oral absorption of biologics. Pharmaceutical and technological strategies including use of absorption enhancers, enzyme inhibition, chemical modification (PEGylation, pro-drug approach, peptidomimetics, glycosylation), particulate delivery (polymeric nanoparticles, liposomes, micelles, microspheres), site-specific delivery in the gastrointestinal tract (GIT), membrane transporters, novel approaches (self-nanoemulsifying drug delivery systems, Eligen technology, Peptelligence, self-assembling bubble carrier approach, luminal unfolding microneedle injector, microneedles) and lymphatic targeting, are discussed. Limitations of these strategies and possible innovations for improving oral bioavailability of protein and peptide drugs are discussed.

Conclusion

This review underlines the application of oral route for peptide and protein delivery, which can direct the formulation scientist for better exploitation of this route.

The influence of mannose-based esters on the mesophase behaviour of lyotropic liquid crystalline nanosystems as drug delivery vectors

Lyotropic Liquid Crystalline (LLC) nanoparticles represent an emerging class of smart, biocompatible, and biodegradable systems for the delivery of drugs. Among these, structures with complex 3D architectures such as cubosomes are of particular interest. These are non- lamellar assemblies having hydrophobic and hydrophilic portions able to carry drugs of different nature. They can further be modulated including suitable additives to control the release of the active payload, and to promote an active targeting. Starting from monoolein (GMO) cubic phase, different concentrations of mannose-based esters were added, and the eventual structural modifications were monitored to ascertain the effects of the presence of glycolipids. Moreover, the structural properties of these nanosystems loaded with Dexamethasone (DEX), a very well-known anti-inflammatory steroid, were also studied. Experiments were carried out by synchrotron Small Angle X-ray Scattering (SAXS), Raman Microspectroscopy (RMS) and Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) measurements. The drug delivery potential (i.e. entrapment efficiency and release properties) of the obtained nanoparticles was evaluated. Finally, in vitro cytocompatibility and anti-inflammatory activity studies of the prepared formulations were carried out. Inclusion of mannose-based surfactants up to 10 mol% influenced the structural parameters of Im3m cubic phase and swollen cubic phases were obtained with the different glycolipids with lattice parameters significantly higher than GMO. A complete cytocompatibility and an increased DEX activity were observed, thus suggesting the possibility to use GMO/glycolipids nanoparticles to formulate innovative drug delivery systems.

Sugar-Based Monoester Surfactants: Synthetic Methodologies, Properties, and Biological Activities

Glycolipids are biocompatible and biodegradable amphiphilic compounds characterized by a great scientific interest for their potential applications in various technological areas, including pharmaceuticals, cosmetics, agriculture, and food production. This report summarizes the available synthetic methodologies, physicochemical properties, and biological activity of sugar fatty acid ester surfactants, with a particular focus on 6-O-glucose, 6-O-mannose, 6-O-sucrose, and 6'-O-lactose ones. In detail, the synthetic approaches to this class of compounds, such as enzymatic lipase-catalyzed and traditional chemical (e.g., acyl chloride, Steglich, Mitsunobu) esterifications, are reported. Moreover, aspects related to the surface activity of these amphiphiles, such as their ability to decrease surface tension, critical micelle concentration, and emulsifying and foaming ability, are described. Biological applications with a focus on the permeability-enhancing effect across the skin or mucosa, antimicrobial and antifungal activities, as well as antibiofilm properties, are also presented. The information reported here on sugar-based ester surfactants is helpful to broaden the interest and the possible innovative applications of this class of amphiphiles in different technological fields in the future.