Paclitaxel is a diterpenoid pseudoalkaloid, isolated from Taxus brevifolia, and is largely used as an antitumoral drug. The formulation of paclitaxel known as Taxol® employs a mixture of Cremophor EL and dehydrated ethanol, due the low drug water solubility. However, Taxol® causes some unwanted side effects due to the presence of Cremophor EL and ethanol in the formulation. Based on this, there is a need for the development of drug delivery systems to enhance the solubility, permeability and stability of paclitaxel and to promote a controlled and targeted delivery for better therapeutic effect and reduced side effects. In addition, the drug has been qualitatively and quantitatively analyzed in different delivery systems. In this context, several approaches were reported focusing on the optimization of analytical methods and development of new ones, considering the need of a fast, simple, with enough sensibility and selectivity assay, which can be a problem in some analysis. This review presents a summary of methods used in quantification of paclitaxel in different matrices, such as plasma, urine, plant extract, cells and delivery systems.

Curcumin, a natural compound extracted from turmeric (Curcuma longa), has been extensively studied because of its various pharmacological properties, such as anti-inflammatory, antioxidant, antibiotic, antiprotozoal, immunomodulatory, anti-proliferative, antitumor, and anticarcinogenic effects. However, low solubility in aqueous media has limited its therapeutic applications. To overcome these bioavailability issues, the use of drug delivery systems providing localized or targeted delivery of this drug may represent a more viable therapeutic option. Several drug delivery systems have been shown to significantly enhance the therapeutic efficacy of curcumin. Additionally, a wide variety of analytical methods are available for the qualitative and quantitative analysis of curcumin in different matrices, including plant extracts, biological fluids, and drug delivery systems. There are a variety of methodologies to quantify curcumin, but chromatographic and spectroscopic techniques are the ones most commonly used. Thus, in this review, we evaluate the biological properties of curcumin, as well as its nanotechnology-based delivery systems and methods of analysis.