Written by Tabish Mehraj, PhD. In this study, a significant increase in bioavailability with micellar formulation was observed, with 18.9-fold higher Cmax (95% CI: 1.9–30.7 ng/mL vs. 74.4–288.3 ng/mL; p = 0.007) vs. 178–612.5 ng·h/mL; p = 0.015). Tmax was 0.5 (95% CI:0.5–4.0) hours for the micellar formulation versus 2.5 (95% CI: 0.5–8.0) hours. No adverse events were observed in either group. Compared to the standard, the micellar formulation showed superior pharmacokinetic outcomes.

Silymarin, a compound derived from the milk thistle plant (Silybum marianum), supports liver health and has antioxidant and anti-inflammatory effects; therefore, it has been extensively studied for the treatment of liver diseases such as hepatitis and alcoholic fatty liver disease. Silymarin’s poor absorption in the gut can limit its health benefits. In this study, a micellar formulation increases oral bioavailability of silymarin about 11-fold was observed. Increased bioavailability could potentially improve the health benefits, possibly at lower dose with better tolerability.

This double-blind, randomized, crossover human trial enrolled 16 healthy adults, including 8 men and 8 women, with a mean age of 39.5 years and a mean BMI of 23.7 kg/m². Participants received a single 130-mg dose of either LipoMicel® Milk Thistle (LMM), a lipid-mediated self-assembling micellar formulation, or a standard unformulated milk thistle extract (STD), followed by a 1-week washout period before receiving the alternate treatment. Blood samples were collected over 24 hours, and total silymarin concentrations were quantified using liquid chromatography-high-resolution mass spectrometry. Pharmacokinetic outcomes included maximum plasma concentration (Cmax), time to maximum concentration (Tmax), area under the concentration-time curve from 0–24 hours (AUC0–24), elimination half-life, and mean residence time (MRT). Safety and tolerability were assessed through adverse-event monitoring and liver and kidney function markers.

Results/Key Findings

• The micellar silymarin (LMM) formulation greatly improved absorption compared with the standard formulation (STD), with 18.9-fold higher Cmax and 11.4-fold higher AUC₀–₂₄ (p = 0.007 and p = 0.015).
• LMM was absorbed much faster, reaching peak levels in 0.5 hours compared with 2.5 hours for STD (p = 0.015).
• The standard formulation stayed in the body longer, but there was no significant difference in elimination half-life between the two formulations.
• No adverse effects or clinically important blood chemistry changes were reported during the 24-hour study period.
• Laboratory analysis confirmed that LMM formed colloidal structures in water, supporting its ability to improve silymarin delivery and absorption.

There are several strengths to the study, as it was a randomized, double-blind, crossover design, which allowed each participant to serve as their own control and reduced between-person variability. The study also used a standardized 130-mg dose and a defined washout period. Pharmacokinetic assessment included multiple blood-sampling time points over 24 hours, allowing detailed characterization of absorption and systemic exposure. The use of validated LC-HRMS methodology provided sensitive and specific measurement of silymarin compounds. In addition, statistical analyses accounted for the distribution of pharmacokinetic variables and included correction for multiple comparisons. All participants completed both treatment periods, with no loss to follow-up. The main limitation was the small sample size and enrollment of healthy adults, which limits generalizability to patients with liver diseases. The study evaluated only a single dose and followed participants for 24 hours; therefore, long-term efficacy and safety could not be determined. Bio-availability of this formulation is not superior compared to Siliphos soft-gel formulation (phytosome). The emphasis should be given that overall the study is pharmacokinetic in nature not an efficacy study. Although the study was described as double-blind, the LMM and STD capsules differed in physical form, potentially compromising blinding. The formulation was also not directly compared with other advanced silymarin delivery systems, such as phytosomes.

LipoMicel® silymarin demonstrated markedly greater systemic exposure and faster absorption than conventional unformulated silymarin, while maintaining short-term tolerability. The findings support the potential of lipid-mediated micellar delivery to improve the oral bioavailability of silymarin. However, larger clinical studies involving diverse patient populations, longer follow-up, excipient-controlled designs, and comparisons with established advanced formulations are needed to determine whether the pharmacokinetic advantages translate into meaningful clinical benefits.

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Posted October 6, 2026.

Dr. Tabish Mehraj is a pharmaceutical scientist with expertise in pharmaceutics, drug delivery, and formulation development. She earned her PhD in Pharmaceutical Sciences from the University of Mississippi, where her research focused on the formulation, optimization, and characterization of lipid-based nanocarriers for targeted liver delivery of antimalarial therapeutics. Dr. Mehraj has also served as an ORISE Fellow at the U.S. Food and Drug Administration (FDA), where she evaluated the effects of formulation and process design on the quality and performance of intravaginal drug delivery systems and developed bio-relevant in vitro drug release testing methods. She has teaching experience in pharmaceutical and life sciences courses and has authored peer-reviewed publications, book chapters, and conference presentations. Dr. Mehraj is an active member of the American Association of Pharmaceutical Scientists and has been recognized by honor societies including Rho Chi and Gamma Beta Phi.

Reference:

1. Chang, C., Zhang, Y., Kuo, Y. C., Du, M., Roh, K., Gahler, R., … & Solnier, J. (2025). Novel micellar formulation of silymarin (milk thistle) with enhanced bioavailability in a double-blind, randomized, crossover human trial. Pharmaceutics, 17(7), 880.