Optimization of skin permeation and distribution of ibuprofen by using nanostructures (coagels) based on alkyl vitamin C derivatives.
In this investigation two vitamin C-based -6-O-ascorbic acid esters (ASC₁₂ and ASC₁₆), able to form liquid-crystal structures (coagels) was evaluated for their potential usefulness to promote the permeation and distribution of ibuprofen (IBU). Two coagel formulations and the same coagels added of polyethylene glycol (PEG-400) were assayed in comparison with a commercial product (Arfen®) by using hairless rat skin as model. The ASC₁₆ and ASC₁₂ derivatives gave rise to stable supramolecular assemblies in water and in water/PEG mixtures (coagels), allowing the solubilization of IBU (0.85%) and producing a IBU controlled release systems, as evidenced by the dynamic dialyse test: the n values were near 1.0, indicative of a linear kinetic, for all coagel formulations, except for the ASC₁₂PEG/C formulation (n=1.51). Our results evidenced the enhancement activity of coagels and the synergic effect of the combination with PEG: all coagels showed a higher amount of IBU permeated through the skin compared to commercial Arfen® with an enhancement factor of 52.94 and 21.53 for ASC₁₂PEG/C and ASC₁₆/C respectively. Otherwise, coagels formulations appeared to produce a low IBU depot in the skin and in the same order of magnitude in epidermis and derma, in spite of significant increase of IBU cutaneous permeation. The positive synergic effect of the coagel-PEG mixtures was demonstrated by the high amount of IBU accumulated in the upper skin layers. The effect of the coagels on the IBU skin permeation and distribution depending on their hydro-lipophilic character could allow a rational design and an optimization of topical formulations.
Saino
V
V
Department of Pharmaceutical Sciences, University of Pisa, Pisa, Italy.
Monti
D
D
Burgalassi
S
S
Tampucci
S
S
Palma
S
S
Allemandi
D
D
Chetoni
P
P
D000279:Administration, Cutaneous; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics* / Q000494:pharmacology; D001205:Ascorbic Acid / Q000031:analogs & derivatives; D016503:Drug Delivery Systems; D007052:Ibuprofen / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics* / Q000494:pharmacology; D008297:Male; D049329:Nanostructures; D010539:Permeability / Q000187:drug effects; D011092:Polyethylene Glycols; D051381:Rats; D054772:Rats, Hairless; D012867:Skin / Q000187:drug effects / Q000378:metabolism*; D012869:Skin Absorption
D000894:Anti-Inflammatory Agents, Non-Steroidal; D011092:Polyethylene Glycols; D001205:Ascorbic Acid; D007052:Ibuprofen