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Aloe vera; hydrogels; acemannan; Carbomer 940;
Chemical composition and therapeutic properties of Aloe vera (L.) Burman f. (A.
vera) explain its potential use in cosmetic, nutritional and pharmaceutical applications.
Mucilaginous gel present in the leaves of A. vera is rich in several compounds, mainly
polysaccharides. Most of the reported therapeutic activities of these polysaccharides are
indicated by the presence of glucomannan, with acemannan being the predominant
polysaccharide. Acemannan has been incorporated into commercially available wound
healing products for wound application. The objective of the present work has
developed a hydrogel for topical use containing mucilage of A. vera to use in skin
disease like psoriasis. The hydrogels were prepared with 80% (w / w) of A. vera
mucilage, varying two types of polymer (anion and nonionic) carbomer 940 1% (FC1
and FC2) or hydroxyethylcellulose 2% (FH3 and FH4), as well as preservatives,
antioxidants and sequestrants. Polysaccharide fractions were extracted from the
mucilage. All of them were used as a group of chemical markers and characterized by
X-ray diffraction, infrared (IR) spectroscopy and nuclear magnetic resonance (NMR).
The quantification of these markers in the raw material, mucilage, and in the hydrogel
was carried out using spectrophotometric techniques in the UV-VIS region. Four
hydrogels (FC1, FC2, FH3 and FH4) were obtained from the mucilage of A. vera and
evaluated for their organoleptic, rheological, pH and acemannan content. The hydrogels
FH3 and FH4 (hydroxyethylcellulose) presented acemannan content of 6.76 and 4.01
mg / g, respectively, FH4 presented pH 4.6 and FH3 showed reoptic behaviour. The
carbomer formulations FC1 and FC2 presented acemannan content of 8.69 mg / g and
9.17 mg / g, respectively, ideal pH for application in psoriasis, good spreadability,
rheological behaviour of the pseudoplastic and thixotropic gels, therefore, taking into
account the characteristics ideal for a semi-solid form of topical application.