LAUSR

BackgroundHighly specific biologically active nucleoside and small peptides, sub fragments of collagen, in specific sequences, have attracted increasing attention for their use in the cosmeceutical field. To be effective in improving the skin and treating skin conditions, it is crucial for these cosmetic ingredients to be delivered through the epidermis and into the viable dermis.Area coveredIn this review, skin permeation, metabolism and clinical efficacy evaluation studies with microneedle application on adenosine and collagen sub fragments peptides, such as GHK and KTTKS were discussed. Strategies to counteract fragile and rapid clearance of nucleoside and peptides, such as specific peptide derivatives resistant to protease activity, peptide polymer conjugation, polymer encapsulated peptide delivery system incorporated within microneedles, were also discussed.Expert opinionIn recent years, various types of microneedle systems such as self-dissolving hyaluronic acid microneedle and pre-treat micro array have been introduced for peptides to traverse the epidermis and into the subcutaneous layer by passive permeation. Microneedle approach can bypass stratum corneum that is a major diffusion barrier to peptides, and has offered a potentially revolutionary advance in cosmeceutical application. However, to support claimed benefits of microneedle application, advanced strategies to counteract degradation of nucleoside and peptides in the skin are required.