Development of Orally Disintegrating Tablets of Standardized Rhodiola rosea Extract

Background/Objectives:Rhodiola rosea L. (Crassulaceae), a perennial adaptogenic herb native to Northern Europe, Asia, and North America, is renowned for its therapeutic properties attributed to phenolic compounds including flavonoids, phenylethanoids, phenylpropanoids, and cinnamyl alcohol glycosides. The plant's antioxidant and anti-inflammatory activities align with its traditional use in boosting physical and cognitive performance, reducing fatigue, and improving stress resilience. However, conventional dosage forms present compliance challenges, particularly for vulnerable populations with swallowing difficulties. This study aimed to develop and optimize orally disintegrating tablets (ODTs) containing standardized Rhodiola rosea root and rhizome (RR) dry extract to ensure rapid disintegration and acceptable taste, thereby improving patient compliance. Methods: Dried Rhodiola rosea root and rhizome (particle size 2-3 mm) were extracted using 70% m/m ethanol using the fractionated maceration methodology. The resulting dry RR extract was standardized to 3.0% m/m rosavin content by blending batches of the extract and analyzed using validated chromatographic methods. The standardized dry extract was formulated into ODTs via direct compression technology. Various excipients were evaluated to achieve rapid disintegration while masking the characteristic bitter taste of RR extract. Results: The optimized ODT formulation (500 mg, 11 mm ø, 20% standardized RR dry extract) disintegrated within 3 min and effectively masking the characteristic bitterness of the RR extract. The formulation maintained content uniformity and did not exhibit loss of active compounds during processing, meeting European Pharmacopoeia requirements for ODTs. Conclusions: The developed ODTs containing standardized Rhodiola rosea extract offer a patient-friendly alternative for oro-mucosal administration, supporting improved compliance in populations with swallowing difficulties while retaining the extract's phytochemical integrity and sensory acceptability.