Advances in Drug Delivery Systems for Lipophilic Drug Paclitaxel: Developments, Challenges, and Opportunities (A Review)

Paclitaxel is one of the most widely utilized anticancer drug. It displays a range of antitumor action, particularly against ovarian cancer, urologic malignancies, head tumor, and Kaposi’s sarcoma. However, due to its highly lipophilic nature, poor fluid dissolvability of less 0.01 mg/mL and lack of ionizing functionalities which may enhance its solubility, there are substantial challenges associated with Paclitaxel delivery. Paclitaxel exhibited promising effects when formulated in combination with ethanol and Cremophor EL, as Taxol®. However, it is associated with various side effects, including hypersensitivity, hypotension, and peripheral neuropathy. The albumin-based Paclitaxel, Abraxane®, is a superior alternative to Taxol® as it diminishes the side effects related to Cremophor EL. Abraxane® is regarded as the gold standard for cancer treatment, but its 21% response rate suggests that more research is needed. Furthermore, the large-scale clinical use of this drug has faced considerable delay because of the absence of suitable delivery vehicles. Therefore, necessitates is the development of an alternate form of Paclitaxel that has both superior aqueous solubility as well as fewer side-effects. During the last decade, various methodologies have been explored to improve Paclitaxel’s solubility with the help of co-solvents and inclusion complexes. Additionally, various methodologies report of passive targeting of cancer cells using nanoparticles, nanosuspensions, Rotaxane (a mechanically interlocked molecular system), liposomes, micelles, emulsions, gels, pastes, etc. Herein, we have comprised a brief report on various delivery techniques for Paclitaxel with improved therapeutic outcomes.