Desenvolvimento de formulações semissólidas contendo extrato seco padronizado de Libidibia ferrea

Abstract

Medicinal plants are commonly used in the prevention and fight against various diseases. In recent years, it uses has been intensified in traditional medicine mainly as wound healing treatment. In face of a rich biodiversity and being the holder of a third of the world's flora, Brazil has an enormous potential in the generation of products and processes of natural origin medicines. A promising candidate for the development of an herbal product is the species Libidibia ferrea, popularly known as “jucá”, commonly used for several purposes, among them as a healing treatment, anti-inflammatory, antimicrobial and analgesic agent. Since drugs are based on dry plant extracts, it has great relevance and possess several advantages such as: dosage accuracy, ease handling, storage, and stability. It also facilitates the incorporation in pharmaceutical formulations so they can be used to obtain products for topical therapy. The objective of this study was to develop a stable semi-solid phytotherapic formulation using standardized “jucá” dry plant extract as an active agent. The vegetable raw material of L. ferrea was characterized and presented values within the recommended range: loss on drying of 10.64%, the total ash content of 2.39%, the extractive content of 51.09%, average particle diameter of 655 μm and the classification of a moderately coarse powder. The chemical characterization showed a total polyphenol content of 5.67%, total tannin content above the minimum of 9.0% established by the Brazilian Pharmacopeia (2019) with a value of 11.70% and quantification of gallic acid of 6.40% against the recommending content of at least 1%. The 7.5% “jucá” Extractive Solution presented a relative density of 1.01, a dry residue of 2.83%, slightly acidic (pH = 3.72) indicating a stable product for phenolic constituents, with content of 17.03% of total polyphenols (151.16 ± 3.19 μg Eq Gallic acid/mL), acquired by HPLC and with values of 1.3776 mg/g of gallic acid content and 11.9394 mg/g for ellagic acid. In addition, vibrational bands characteristic of phenolic compounds was found by FTIR analysis. The operational efficiency of drying the spray dried extract (76.26%) was satisfactory, residual humidity of 6.80% and low water activity (0.19) stablish that it can remain stable with low risks of microorganism development. It was classified macroscopically as a fine powder with agglomerations of light brown color and characteristic odor of this species. The scanning electron microscope showed particles with spherical, hollow shape and rough surface. It was observed that the drying in Spray Dryer influenced the increase in the concentration of total polyphenols, with a content of 40.6% (382.61 μg eq. Gallic acid/mL), a fact also observed in FTIR. The chromatographic profile showed the presence of 4.0392 mg/g of gallic acid and 9.1529 mg/g of ellagic acid. The spray dried extract (SPE) maintained the cell viability of fibroblasts for a period of 72 hours, a good free radical scavenger in in vitro tests by the DPPH method • with an IC50 of 8.84 µg/mL and ABTS • + of 5.23 µg/mL. The SPE showed potential antimicrobial activity against S. aureus CBAM 0324 with a 20 mm inhibition zone at a concentration of 75 mg/mL, like the vancomycin standard. There were no significant differences (p> 0.05) between the concentrations of 2.5%, 5% and 7.5% of SPE compared to S. aureus ATC 29213 and ATCC 43300 and for both, an MIC = 400 µg/mL was obtained. Preliminary tests showed that formulations B30 and B40 were compatible with the SPE of “jucá”, up to a concentration of 5%. The optimized formulation B40 containing the addition lanolin proved to be stable and within the initial expectations of improving its spreadability, suggesting it as vehicle with the potential to incorporate dry “jucá” extract. Formulation B43 had the best rheological profile, highest antioxidant capacity and total phenol, and showed best stability with storage at room temperature for up to 30 days.