Design and Evaluation of Hydrophobic Ion Paired Insulin Loaded Self Micro-Emulsifying Drug Delivery System for Oral Delivery

Hydrophobic ion pairing: lipophilicity improvement of anionic macromolecules by divalent cation mediated complex formation

The aim of this study was to develop an alternative strategy to sufficiently increase the lipophilicity of anionic model macromolecules (MM) without the use of cationic counterions. Enoxaparin (ENO), insulin (INS) and poly-L-glutamic acid (PLG) were ion paired with anionic surfactants (sodium decanoate (DEC), sodium dodecyl sulfate (SDS), sodium stearate (SS) and sodium octadecyl sulfate (SOS)), mediated by divalent cations such as magnesium, calcium and zinc. Complexes were evaluated regarding their precipitation efficiency and logDn-butanol/water. SEDDS were developed, loaded with the complexes and characterized for their size and stability. Finally, payloads and logDSEDDS/release medium were determined. Divalent cation mediated ENO, INS and PLG complexes were successfully formed as underlined by high precipitation efficiencies above 90% in case of Zn2+-mediated complexes. Most pronounced increase in logDn-butanol/water was achieved for ENO-Zn2+-SOS (1.85), INS-Zn2+-SOS (0.80) and PLG-Zn2+-SS (0.48) providing suitable solubilities in commonly used SEDDS components. Developed SEDDS displayed droplet sizes below 200 nm without major changes after loading with MM complexes. Payloads up to 18.72 mg/ml could be achieved in developed SEDDS for ENO-Zn2+-SOS, and 2.44 mg/ml and 6.93 mg/ml for INS-Zn2+-SOS and PLG-Zn2+-SS, respectively. In general, highest lipophilicity enhancement and thus solubility in SEDDS was obtained with Zn2+-mediated complexes among the investigated cations and particularly with the highly negatively charged polysaccharide ENO. The formation of complexes between anionic MM and anionic surfactants mediated by divalent cations, substituting normally used cationic counterions exhibiting higher toxicity, offers a promising alternative to enhance their lipophilicity for oral drug delivery.

A Comprehensive Review of Hydrogel-Based Drug Delivery Systems: Classification, Properties, Recent Trends, and Applications

As adaptable biomaterials, hydrogels have shown great promise in several industries, which include the delivery of drugs, engineering of tissues, biosensing, and regenerative medicine. These hydrophilic polymer three-dimensional networks have special qualities like increased content of water, soft, flexible nature, as well as biocompatibility, which makes it excellent candidates for simulating the extracellular matrix and promoting cell development and tissue regeneration. With an emphasis on their design concepts, synthesis processes, and characterization procedures, this review paper offers a thorough overview of hydrogels. It covers the various hydrogel material types, such as natural polymers, synthetic polymers, and hybrid hydrogels, as well as their unique characteristics and uses. The improvements in hydrogel-based platforms for controlled drug delivery are examined. It also looks at recent advances in bioprinting methods that use hydrogels to create intricate tissue constructions with exquisite spatial control. The performance of hydrogels is explored through several variables, including mechanical properties, degradation behaviour, and biological interactions, with a focus on the significance of customizing hydrogel qualities for particular applications. This review paper also offers insights into future directions in hydrogel research, including those that promise to advance the discipline, such as stimuli-responsive hydrogels, self-healing hydrogels, and bioactive hydrogels. Generally, the objective of this review paper is to provide readers with a detailed grasp of hydrogels and all of their potential uses, making it an invaluable tool for scientists and researchers studying biomaterials and tissue engineering.

A review on oral novel delivery systems of insulin through the novel delivery system formulations: A review

Parenteral administration of insulin remains the most common route of administration, causing local hypertrophy at the injection sites because of multiple daily injections. Because of this, there is an interest and effort in oral insulin administration that is convenient and mimics the physiology of endogenous insulin secreted in the liver. However, oral insulin encountered different challenges due to abundant enzyme degradation, the presence of a mucus layer, and the underlying intestinal epithelial membrane barrier in the gastrointestinal tract. This narrative review reviewed the literature dealing with novel oral insulin delivery approaches. Various pieces of literature were searched, filtered, and reviewed from different sources, and the information obtained was organized, formulated, and finalized. Oral insulin has been formulated and extensively studied in various novel delivery approaches, such as nanoparticles, microspheres, mucoadhesive patches, encapsulations, hydrogels, ionic liquids, liposomes, and complexation. The efficiency of these formulations demonstrated improved efficiency and potency compared to free oral insulin delivery, but none of them have greater or equivalent potency to subcutaneous insulin. Future studies regarding dose-dependent therapeutic efficacy and the development of new novel formulations to produce comparable oral insulin to subcutaneous insulin are warranted to further support the suitability of the current platform for oral insulin delivery.