Liberation of polyphenols of different agrimony extracts from topical preparations

Agrimony belongs to one of the most famous middle-European medicinal plants widely used in traditional medicine. The study aimed to formulate a topical preparation of the hydro-ointment type intended to treat minor skin inflammation and small, superficial wounds. Three gel-forming bases containing hydroxyethyl cellulose, carboxymethyl cellulose and Carbopol 940 were evaluated. MeOH, 50% MeOH, and H₂O lyophilized extracts of agrimony served as active ingredients. The suitability of gel-forming bases was assessed based on total phenolic liberating capability. The liberation of extracts was performed in vitro through a semipermeable membrane using a vertical Franz diffusion cell system. The total polyphenolics quantity was determined spectrophotometrically by reaction with Folin-Ciocalteu's reagent. The cumulative amount of polyphenols released through the synthetic membrane from 1% Carbopol gel was 61.3% for H₂O, 67.3% for MeOH and 55.4% for 50% MeOH extract within six hours. In comparison, 4% carboxymethyl cellulose gel released 47.1% (H₂O extract), 55% (MeOH extract) and 39.3% (50% MeOH extract) of total polyphenolics. In a preliminary test of liberation, 5% hydroxyethyl cellulose exhibited the lowest rate of released polyphenolics and was excluded from further experiments. The mutual HPLC comparison of lyophilized extract fingerprints and polyphenolic patterns of topical formulations after liberation exhibit differences in the content and profile of polyphenols. From the administration's viewpoint, the base with 1% Carbopol and 4% carboxymethyl cellulose proved most suitable.

Funding This work was supported by the Grants: VEGA 1/0226/22, and APVV-20-0017.

 

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Conflict of Interest

The authors declare no conflict of interest.

Publication History

Article published online:
16 November 2023