Solidago canadensis L. Herb Extract, Its Amino Acids Preparations and 3D-Printed Dosage Forms: Phytochemical, Technological, Molecular Docking and Pharmacological Research

<b>Background/Objectives</b>: The Canadian goldenrod (<i>Solidago canadensis</i> L.) is one of the most widespread species of the genus <i>Solidago</i> from the Asteraceae family. It has a rich composition of biologically active compounds and is traditionally used to address kidney, urinary tract, and liver diseases. Previously, it was proven that the <i>S. canadensis</i> extract obtained with a 40% ethanol solution had the most promising anti-inflammatory and hepatoprotective activity. Therefore, this extract was selected for the further formulation of amino acid preparations and 3D-printed dosage forms. The aims of the present study were to investigate the chemical composition, toxicity, and antimicrobial, anti-inflammatory, and hepatoprotective activity of <i>S. canadensis</i> dry extract, its amino acid preparations, and 3D-printed dosage forms. <b>Results</b>: A total of 18 phenolic compounds and 14 amino acids were determined in the extracts. The <i>S. canadensis</i> herb extracts were verified to be practically non-toxic preparations (toxicity class V, LD₅₀ > 5000 mg/kg). They also showed moderate antimicrobial activity against <i>Staphylococcus aureus</i>, <i>Enterococcus faecalis,</i> and β-hemolytic <i>Streptococcus pyogenes</i>. The most pronounced hepatoprotective activity was observed with <i>S. canadensis</i> herb extract and its amino acid preparations with phenylalanine, alanine, and lysine at a dose of 25 mg/kg body weight. The most pronounced anti-inflammatory activity was found with <i>S. canadensis</i> herb extract and its preparation with arginine. According to the calculated docking score array and the analysis of binding modes in the active sites of COX-1 and COX-2, the flavonoid fraction and caffeic acid in the <i>S. canadensis</i> extracts presented moderate inhibitory activity. <b>Conclusions</b>: The development of innovative 3D-printed oral dosage forms represents a promising strategy to formulate dietary supplements or pharmaceutical preparations for these herbal extracts.