Analysis of docosanol using GC/MS:Method development,validation,and application to ex vivo human skin permeation studies / 药物分析学报

Docosanol is the only US Food and Drug Administration(FDA)approved over-the-counter topical product for treating recurrent oral-facial herpes simplex labialis.Validated analytical methods for docosanol are required to demonstrate the bioequivalence of docosanol topical products.A gas chromatography/selected ion monitoring mode mass spectrometry(GC/SIM-MS)method was developed and validated for docosanol determination in biological samples.Docosanol and isopropyl palmitate(internal standard)were separated on a high-polarity GC capillary column with(88％cyanopropy)aryl-polysiloxane employed as the stationary phase.The ions of m/z 83 and 256 were selected to monitor docosanol and isopropyl palmitate,respectively;the total run time was 20 min.The GC/SIM-MS method was validated in accordance with US FDA guidelines,and the results met the US FDA acceptance criteria.The docosanol calibration standards were linear in the 100-10000 ng/mL concentration range(R2＞0.994).The recoveries for docosanol from the receptor fluid and skin homogenates were＞93.2％and＞95.8％,respectively.The validated method was successfully applied to analyze ex vivo human cadaver skin permeation samples.On applying Abreva?cream tube and Abreva?cream pump,the amount of doco-sanol that penetrated human cadaver skin at 48 h was 21.5±7.01 and 24.0±6.95 ng/mg,respectively.Accordingly,we concluded that the validated GC/SIM-MS was sensitive,specific,and suitable for quantifying docosanol as a quality control tool.This method can be used for routine analysis as a cost-effective alternative to other techniques.

Microscopic characterization and HPTLC of the leaves, stems and roots of Fadogia agrestis - an African folk medicinal plant

ABSTRACT Fadogia agrestis Schweinf. ex Hiern (Vangueria agrestis (Schweinf. ex Hiern) Lantz), Rubiaceae, is an African traditional medicinal plant also used as a dietary supplement in the US. The present paper is the first report of the pharmacognostic study of the leaf, stem and root of F. agrestis by microscopy, HPTLC and total phenolic/flavonoid content analyses. Noteworthy microscopic features that can help in identification and quality control are septate and lignified non-glandular trichomes on leaf and stem epidermises, paracytic stomata on leaf abaxial epidermis, numerous cells containing yellow substances of presumably phenolic compounds in leaf and stem, calcium oxalate druses and prismatic crystals in leaf and styloids in stem, primary phloem fibers in stem, brachysclereids in stem and root, spherical starch grains in root, and vessels with vestured pits and simple perforated end walls. In addition to microscopy, a total phenolic/flavonoid content determination and an HPTLC method were also developed for rapid chemical fingerprint analyses of Fadogia samples and dietary supplements.

Euphorbia umbellata bark extracts – an in vitro cytotoxic study

ABSTRACT Euphorbia umbellata (Pax) Bruyns, Euphorbiaceae, is commonly used in folk medicine of southern Brazil to treat several kinds of cancer. The latex (part of the plant used for this purpose) is mixed with water and taken as treatment; but this matrix contains toxic potential related to the presence of some phorbol type diterpenes. So the aim of this study was to evaluate the cytotoxicity of the crude extract of the bark of E. umbellata and its fractions (Hex, CHCl3, EtOAc and MeOH) using in vitro assay (applying Jurkat cells line). A preliminary cytotoxic study (MTT reduction, trypan blue exclusion and DNA quantification assays) was executed to identify the most active material. The CHCl3 fraction displayed the highest activity and was selected for further investigation of any cytotoxic mechanism and evaluation of chemical composition; flow cytometry, Acridine orange and Hoechst 33342 staining experiments and Gas chromatography–mass spectrometry analysis were applied to achieve these results. This fraction demonstrated the best cytotoxic results against Jurkat cells line with IC50 of 29.00 ± 1.49, 10.06 ± 1.48 and 4.83 ± 2.25 µg/ml for 24, 48 and 72 h of experiment, respectively (trypan blue exclusion). The mechanism responsible for this action can be associated with the promotion of cell cycle arrest and apoptosis. The two main classes of compounds present in the CHCl3 fraction are steroids and triterpenes. Further, phytochemical studies with this fraction need to be evaluated, to try isolating these substances and establishing a more detailed cytotoxic study against Jurkat cells.