Formulation and Manufacturing Process of Softgel Capsules Containing Common Butterbur RootExtract: A Stability Study and Method of Analysis

<i>Butterbur</i> root extract offers several health benefits, including anti-inflammatory and antiallergic activities, and developing a standardized, stable finished product of butterbur extract is essential to ensure therapeutic efficacy. This study aimed to present the formulation and manufacturing approach for creating a stable, effective, and aesthetically appealing softgel formulation of <i>butterbur</i> root extract. Each softgel capsule contained purple <i>butterbur</i> root extract (50 mg), lecithin (20 mg), soybean oil (185 mg), and beeswax yellow (10 mg). Stability testing included capsule and fill content weight, capsule rupture time, microbial evaluation, and petasins analysis under both accelerated and real-time conditions for three product lots. Petasins extracted from <i>butterbur</i> root extract were analyzed using a validated HPLC method, with percentage recovery ranging from 101.3% to 105.15%. The percent standard deviation for intraday and interday results was 0.29 to 0.31 and 0.39 to 0.79, respectively. This study demonstrated the formulation of softgel capsules containing <i>butterbur</i> root extract, effective petasins extraction, a validated method for petasins analysis, and 2-year product stability. It establishes a reliable approach for petasins analysis and the formulation of a <i>butterbur</i>-based herbal product.