Betulinic Acid Nanogels: Rheological, Microstructural Characterization and Evaluation of their Anti-inflammatory Activity.
BACKGROUND
Betulinic Acid (BA) is a lipophilic compound with proven beneficial results in topical inflammation. Nanogels (NG) are carriers of bioactive compounds with properties that make them good candidates to treat skin diseases.


OBJECTIVE
The objective of this study was to evaluate the anti-inflammatory activity of BA carried in NG.


METHODS
NG were composed of a nanoemulsion and a crosslinking agent (Carbopol 940®) applied at three concentrations (0.5, 1, and 1.5 %) and three activation times (6, 12 and 24 h). In order to select the optimal formulation, the NG were characterized mechanically and micro-structurally followed by evaluation of the BA anti-inflammatory activity in an in vivo model of auricular edema. We determined the edema inhibition activity as percent weight. Additionally, the anti-inflammatory activity of NG was validated through histological analysis.


RESULTS
The formulation with the best viscoelastic properties was the one prepared with 0.5% carbopol and 6 h of activation. Microstructural examination of this formulation showed mostly spherical structures with a mean diameter of 65 nm. From the evaluation of edema and the histological analyses, we established that the NG of BA produced 52% inhibition. In contrast, a conventional gel and free BA produced 28% and 19% inhibition, respectively.


CONCLUSION
The NG of BA were found to be good vehicles to treat skin inflammation.
['Sosa-Gutierrez|Dalis S|DS|', 'Toro-Vazquez|Jorge F|JF|', 'Cano-Sarmiento|Cynthia|C|', 'Grube-Pagola|Peter|P|', 'Aparicio-Saguilan|Alejandro|A|', 'Torres-Palacios|Cristobal|C|', 'Acosta-Osorio|Andres A|AA|', 'Garcia|Hugo S|HS|']
D000893:Anti-Inflammatory Agents D004487:Edema D006801:Humans D000080385:Nanogels D053978:Pentacyclic Triterpenes D014315:Triterpenes
betulinic acid Nanogel inflammation skin auricular edema microspheres