Self-assembled chitosan-insulin oral nanoparticles - A critical perspective review.

Chitosan is an abundant natural cationic polysaccharide with excellent biodegradability, bioadhesion, and biocompatibility. Chitosan is extensively researched for various particulate oral insulin drug delivery systems. Oral insulin is economically efficient and more convenient than injections, with greater patient compliance. Electrostatic ionic interaction between cationic chitosan and anionic polymer or insulin leads to the formation of spontaneously self-assembled nanoparticles. This simple technique attracted many researchers as it can be carried out quickly in mild conditions without harmful solvents, such as surfactants or chemical cross-linkers that might degrade the insulin structure. The formulated chitosan nanoparticles help to protect the core insulin from enzymatic degradation in the digestive system and improve paracellular intestinal uptake from the enterocytes due to mucoadhesion and reversible tight junction opening. Moreover, functionalized chitosan nanoparticles create newer avenues for targeted and prolonged delivery. This review focuses on modified chitosan-insulin nanoparticles and their implications on oral insulin delivery. Dependent variables and their optimal concentration ranges used in self-assembly techniques for chitosan-insulin nanoparticular synthesis are summarized. This review provides a comprehensive guide to fine-tune the essential factors to formulate stable insulin-chitosan nanoparticles using mild ionic interactions.

Fabrication and Evaluation of Transdermal Microneedles for a Recombinant Human Keratinocyte Growth Factor.

OBJECTIVES: Microneedle transdermal patches are a combination of hypodermic needles and transdermal patches used to overcome the individual limitations of both injections and patches. The objective of this study was to design a minimally invasive, biodegradable polymeric recombinant human keratinocyte growth factor (rHuKGF) microneedle array and evaluate the prepared biodegradable microneedles using in vitro techniques. MATERIALS AND METHODS: Biodegradable polymeric microneedle arrays were fabricated out of poly lactic-co-glycolic acid (PLGA) using the micromolding technique under aseptic conditions, and the morphology of the microneedles was characterized using light microscopy. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to rule out drug-polymer interactions. Standard procedures were used to analyze the prepared microneedle arrays for in vitro drug release and to perform a microneedle insertion test. Enzyme-linked immunosorbent assay was used to quantify rHuKGF. RESULTS: The PLGA polymer was safe for use in the fabrication of rHuKGF microneedles as there was no interaction between the drug and the polymer. The fabricated rHuKGF microneedle arrays had fully formed microneedles with a height of 600 µm and a base of 300 µm. The drug from the microneedle patch was released in vitro within 30 minutes. The strength of the microneedles in the patch was good, as they were able to reach a depth of 381±3.56 µm into parafilm without any structural change or fracture. CONCLUSION: Microneedle transdermal patches were successfully prepared for rHuKGF, and their evaluation suggested excellent quality and uniformity of patch characteristics. This can have potential applications in the therapeutic arena, offering advantages in terms of reduced dosing frequency, improved patient compliance, and bioavailability.