An Investigation of the Influence of PEG 400 and PEG-6-Caprylic/Capric Glycerides on Dermal Delivery of Niacinamide
Polyethylene glycols (PEGs) and PEG derivatives are used in a range of cosmetic and pharmaceutical products. However, few studies have investigated the influence of PEGs and their related derivatives on skin permeation, especially when combined with other solvents. Previously, we reported niacinamide (NIA) skin permeation from a range of neat solvents including propylene glycol (PG), Transcutol® P (TC), dimethyl isosorbide (DMI), PEG 400 and PEG 600. In the present work, binary and ternary systems composed of PEGs or PEG derivatives combined with other solvents were investigated for skin delivery of NIA. In vitro finite dose studies were conducted (5 μL/cm2) in porcine skin over 24 h. Higher skin permeation of NIA was observed for all vehicles compared to PEG 400. However, overall permeation for the binary and ternary systems was comparatively low compared with results for PG, TC and DMI. Interestingly, values for percentage skin retention of NIA for PEG 400:DMI and PEG 400:TC were significantly higher than values for DMI, TC and PG (p < 0.05). The findings suggest that PEG 400 may be a useful component of formulations for the delivery of actives to the skin rather than through the skin. Future studies will expand the range of vehicles investigated and also look at skin absorption and residence time of PEG 400 compared to other solvents.
Download the full article here: An Investigation of the Influence of PEG 400 and PEG-6-Caprylic:Capric Glycerides on Dermal Delivery of Niacinamide
or continue reading here: Zhang, Y.; Lane, M.E.; Moore, D.J. An Investigation of the Influence of PEG 400 and PEG-6-Caprylic/Capric Glycerides on Dermal Delivery of Niacinamide. Polymers 2020, 12, 2907.
Keywords: niacinamide; polyethene glycol (PEG) 400; solvent; dermal delivery; finite dose; porcine skin
Conclusions
PEGs and their derivatives are commonly used in topical and transdermal formulations. Previously, we reported no permeation or skin retention of NIA from a neat PEG 400 solution in porcine skin. The present work examined NIA skin delivery from vehicles composed of PEG 400 and the PEG derivative PEG-6-CCG. Permeation of NIA was increased for the PEG 400 binary systems compared to PEG 400 alone, but overall, very low permeation of NIA was observed. On the other hand, high skin retention was observed for these vehicles when compared with the neat solvents investigated. Depending on the active of interest, skin retention rather than permeation may be more desirable. An assessment of the residence time of PEGs on and in the skin should also allow for a better understanding of how PEGs can be utilized when targeting actives to the skin. This will be the focus of future work, as well as an investigation of the influence of other PEGs and their derivatives on skin delivery of actives.