Hydrogel Formulations for Topical Insulin Application: Preparation, Characterization and In Vitro Permeation across the Strat-M® Membrane

Abstract

Insulin has shown efficacy in the treatment of hard-to-heal wounds, which is mainly due to its role in regulating oxidative stress and inflammatory reactions. The aim of this study was to develop an insulin–hydrogel carrier based on Sepineo™ P 600 and Sepineo™ PHD 100 for application to lesional skin. Preformulation studies of the developed formulations were performed in terms of analysis of the pharmaceutical availability of insulin from the hydrogels through the Strat-M® membrane, and rheological and texture measurements. Insulin is released in a prolonged manner; after a time of 6.5 h, 4.01 IU/cm2 (53.36%) and 3.69 IU/cm2 (47.4%) of the hormone were released from the hydrogel based on Sepineo™ P 600 and Sepineo™ PHD 100, respectively. Rheological analysis showed that the hydrogels tested belong to non-Newtonian, shear-thinning systems with yield stress. The insulin–hydrogel based on Sepineo™ P 600 and Sepineo™ PHD 100 shows optimal application properties. The results obtained provide a basis for further preclinical and clinical studies.

In Vitro and In Vivo Evaluation of Chitosan/HPMC/Insulin Hydrogel for Wound Healing Applications

“…Hydrogels have some essential characteristics for wound dressing, such as the ability to keep the wound bed moist, suitable mechanical properties, and biocompatibility. These properties are maintained in the formulation of Chi/HPMC/Ins hydrogels [13].…”

“…It was hypothesized that the Chi/HPMC/Ins hydrogel might act as a wound dressing due to the properties of its components. Several hydrogel wound dressing formulations have been developed due to the advantages of using these materials [13,[35][36][37][38].…”

“…Insulin is a peptide hormone which exerts functions in different types of body tissue, including the skin. Other studies that investigate topical insulin for wound healing showed it modulates the re-epithelialization process, stimulating cell proliferation and migration of keratinocytes [13,49]. Biodegradable carbohydrate polymers control hydrogel degradation while liberating the hormone in a continued manner [9].…”

“…In hydrogels, insulin is entrapped in the structure, and this allows for prolonged and controlled hormone release into the wound bed [13]. This characteristic could contribute to safety concerning blood glucose levels.…”

“…Among natural compounds, chitosan has attracted researchers' attention due to its properties [11]. This is a hydrophilic polymer [12], and it has amino groups which make it an appropriate compound for the encapsulation and delivery of active ingredients such as insulin [13], magnesium hydroxide [14], LL-37 peptide [15], honey [11], and many others [16][17][18]. Chitosan can act in all stages of wound healing.…”