Processing difficulties and instability of carbohydrate microneedle arrays

摘要: Background: A number of reports have suggested that many the problems currently associated with use microneedle (MN) arrays for transdermal drug delivery could be addressed by using drug-loaded MN prepared moulding hot melts carbohydrate materials. Methods: In this study, we explored processing, handling, and storage from galactose a view to clinical application. Results: Galactose required high processing temperature (160°C), molten was difficult work with. Substantial losses model drugs 5-aminolevulinic acid (ALA) bovine serum albumin were incurred during processing. While relatively small forces caused significant reductions in height when applied an aluminium block, not observed their facile insertion into heat-stripped epidermis. Drug release experiments ALA-loaded revealed less than 0.05% total loading released across silicone membrane. Similarly, only low amounts ALA (approximately 0.13%) undetectable delivered combined aqueous vehicles. Microscopic inspection membrane following studies no holes membrane, indicating partially dissolved sealed MN-induced holes, thus limiting delivery. Indeed, depth penetration excised porcine skin there increase arrays, compared control (P value < 0.05). MNs unstable at ambient relative humidities became adhesive. Conclusion: The difficulties instability encountered study are likely preclude successful application MNs. findings particular importance those pharmaceutical industry involved design formulation systems based on dissolving arrays. It is hoped illustrated conclusively inherent carbohydrate-based will now follow alternative approaches.