Key functions in polymer carriers for intestinal absorption of insulin

A review of polymers as multifunctional excipients in drug dosage form technology

In the article, groups of multifunctional polymers used in drug dosage form technology were classified and evaluated. These compounds, in addition to their basic function as excipients, may have additional properties, e.g. stimuli sensitivity, enzyme inhibition, intestinal epithelium penetration enhancement, efflux pump inhibition, taste-masking, pharmacological activity and the ability to interact with enzymes responsible for drug metabolism. While classifying specific groups of multifunctional polymers, special emphasis was placed on the advantages of using them when designing new drug. Such advantages include, i.a., increasing substance bioavailability, improving substance stability during formulation and the possibility of obtaining forms of controlled or localized release to a specific site in the organism.

Colloidal carrier integrating biomaterials for oral insulin delivery: Influence of component formulation on physicochemical and biological parameters

Strategies to design effective and safe colloidal carriers for biopharmaceuticals have evolved through applying the knowledge gained in nanotechnology to medicine. Designing a colloidal carrier to serve as a protein delivery device requires an understanding of the effect of different materials on the physicochemical, physiological and toxicological parameters for clinical application. The purpose of this study was to evaluate the influence of formulation components on the physicochemical factors and biological function involved in the development and optimization of newly designed nanoparticles for orally dosed insulin. Biodegradable, biocompatible, mucoadhesive and protease-protective biomaterials were combined through ionotropic pre-gelation and polyelectrolyte complexation forming an alginate, dextran sulfate and poloxamer hydrogel containing insulin, stabilized in nanoparticles with chitosan and poly(ethyleneglycol) and coated with albumin. Nanoparticles ranged in size from 200 to 500nm with 70-90% insulin entrapment efficiency, and electrostatic stabilization was suggested by zeta potential values lower than -30mV. This combination of formulation components was selected for insulin protection against harsh gastric pH and proteolytic conditions, and to improve insulin absorption through intestinal mucosa by combining nanoparticle uptake and insulin release at the site of absorption. Insulin was shown to be bioactive after nanoparticle formulation and release in neutral pH conditions. Fourier transform infrared spectroscopy was used to confirm the presence of formulations components in the nanoparticle structure and to identify potential interactions between biomaterials.

Novel platforms for oral drug delivery

The aim of this review is to provide the reader general and inspiring prospects on recent and promising fields of innovation in oral drug delivery. Nowadays, inventive drug delivery systems vary from geometrically modified and modular matrices, more close to "classic" pharmaceutical manufacturing processes, to futuristic bio micro-electro-mechanical systems (bioMEMS), based on manufacturing techniques borrowed from electronics and other fields. In these technologies new materials and creative solutions are essential designing intelligent drug delivery systems able to release the required drug at the proper body location with the correct release rate. In particular, oral drug delivery systems of the future are expected to have a significant impact on the treatment of diseases, such as AIDS, cancer, malaria, diabetes requiring complex and multi-drug therapies, as well as on the life of patients, whose age and/or health status make necessary a multiple pharmacological approach.