Silymarin: an insight to its formulation and analytical prospects

Silymarin, a potential phytochemical compound obtained from the seeds of Silybum marianum plant has been used as a hepatoprotective agent for more than a decade. So far, eight active components of silymarin flavonolignans have been identified, among which silibinin has been proven the most active. However, it had poor oral bioavailability due to extensive phase II metabolism, low permeability across intestinal epithelial cells, low aqueous solubility, and rapid excretion in bile and urine. Therefore it becomes necessary to understand all its formulation and analytical aspects from past to present, including all of its possible future prospects. In modern research scenario, nanotization strategies of drugs has served as a potential approach to enhance solubility, bioavailability and to develop a robust formulation. Several approaches have been utilized previously to enhance the solubility and bioavailability of silymarin to provide it a robust strength against physical, chemical, and environmental degradation. Nanoscale formulations such as nanoemulsion, nanosuspension, liposomes, and solid–lipid nanoparticles can be used to enhance solubility and to target them to desired cells with minimum harm to normal cells. However, many other approaches exist such as dendrimers, ceramic nanoparticles, and carbon nanotubes, which serve as a great vehicle in drug delivery to transport medicament at target sites. Therefore, the purpose of this review was to develop a better understanding of the problems associated with silymarin and approaches to overcome the difficulties to develop a better and stable formulation for food and pharmaceutical applications.