Taxol (paclitaxel) is a cornerstone anticancer agent whose industrial production and clinical use combine pharmacology, chemistry, and biotechnology. B. Pharm students should understand Taxol’s taxane structure, microtubule-stabilizing mechanism, clinical indications (breast, ovarian, lung cancers), toxicity profile (myelosuppression, peripheral neuropathy), and formulation challenges such as cremophor EL hypersensitivity. Industrially, production moved from extraction of yew bark to semisynthesis from 10‑deacetylbaccatin III, plant cell cultures, and microbial sources to ensure sustainability and quality control. Key manufacturing topics include analytical methods (HPLC), scale-up, regulatory issues, and green chemistry approaches. This concise review prepares you for applied questions on production, pharmacology, formulation, and safety. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which natural source originally provided Taxol for early isolation?
- Pacific yew tree bark (Taxus brevifolia)
- Willow tree bark (Salix alba)
- Poppy capsules (Papaver somniferum)
- Cinchona bark (Cinchona spp.)
Correct Answer: Pacific yew tree bark (Taxus brevifolia)
Q2. Paclitaxel belongs to which chemical class?
- Taxane diterpenoid
- Alkaloid
- Anthracycline
- Platinum coordination complex
Correct Answer: Taxane diterpenoid
Q3. Which industrial production method became dominant to reduce reliance on yew bark?
- Semisynthesis from 10‑deacetylbaccatin III
- Total chemical synthesis from simple hydrocarbons
- Direct bark extraction only
- Extraction from marine sponges
Correct Answer: Semisynthesis from 10‑deacetylbaccatin III
Q4. 10‑deacetylbaccatin III is typically obtained from which plant material for semisynthesis?
- Yew needles
- Yew roots
- Yew flowers
- Yew fruits
Correct Answer: Yew needles
Q5. Why is total synthesis of paclitaxel not commonly used for commercial production?
- It is too complex, low-yielding, and economically unattractive
- It produces an inactive isomer exclusively
- It leads to dangerous byproducts not removable by purification
- It requires marine organisms as catalysts
Correct Answer: It is too complex, low-yielding, and economically unattractive
Q6. Which biotechnological method is used to produce paclitaxel without harvesting whole trees?
- Plant cell suspension culture of Taxus species
- Transgenic bacterial production of full paclitaxel
- Fermentation of yeast producing the final drug without modification
- Hydroponic cultivation of Taxus saplings only
Correct Answer: Plant cell suspension culture of Taxus species
Q7. Which excipient in traditional Taxol formulation is associated with hypersensitivity reactions?
- Cremophor EL (polyoxyethylated castor oil)
- Sodium chloride
- Polysorbate 80
- Lactose monohydrate
Correct Answer: Cremophor EL (polyoxyethylated castor oil)
Q8. What is the primary molecular mechanism of paclitaxel’s anticancer activity?
- Stabilization of microtubules preventing depolymerization
- Inhibition of DNA topoisomerase II
- Intercalation into DNA duplexes
- Alkylation of guanine bases
Correct Answer: Stabilization of microtubules preventing depolymerization
Q9. Which of the following is a main clinical indication for paclitaxel?
- Breast and ovarian cancer
- Type 2 diabetes mellitus
- Essential hypertension
- Rheumatoid arthritis
Correct Answer: Breast and ovarian cancer
Q10. What is the dose-limiting toxicity commonly associated with paclitaxel?
- Neutropenia (myelosuppression)
- Hepatotoxicity only
- Severe hypertension
- Renal failure
Correct Answer: Neutropenia (myelosuppression)
Q11. Which long-term adverse effect is characteristic of paclitaxel therapy?
- Peripheral sensory neuropathy
- Ototoxicity
- Pulmonary fibrosis exclusively
- Retinopathy
Correct Answer: Peripheral sensory neuropathy
Q12. Which cytochrome P450 enzymes are primarily involved in paclitaxel metabolism?
- CYP2C8 and CYP3A4
- CYP1A2 and CYP2D6
- CYP2E1 and CYP2A6
- CYP4A11 and CYP2B6
Correct Answer: CYP2C8 and CYP3A4
Q13. Co-administration of a strong CYP3A4 inhibitor with paclitaxel will most likely cause what?
- Increased paclitaxel plasma concentration and toxicity
- Complete inactivation of paclitaxel
- Increased renal clearance of paclitaxel
- No change in paclitaxel levels
Correct Answer: Increased paclitaxel plasma concentration and toxicity
Q14. A common mechanism of tumor resistance to paclitaxel is:
- Overexpression of P‑glycoprotein efflux pumps
- Increased DNA repair enzymes
- Mutation of topoisomerase I
- Decreased glutathione synthesis only
Correct Answer: Overexpression of P‑glycoprotein efflux pumps
Q15. Which analytical technique is standard for quantifying paclitaxel during production quality control?
- High-performance liquid chromatography (HPLC)
- Infrared spectroscopy only
- Flame photometry
- Simple visual inspection
Correct Answer: High-performance liquid chromatography (HPLC)
Q16. An advantage of semisynthetic production of paclitaxel is:
- Reduced need to harvest slow-growing yew bark
- Elimination of all purification steps
- Complete avoidance of organic solvents
- Production at room temperature without catalysts
Correct Answer: Reduced need to harvest slow-growing yew bark
Q17. Which marketed formulation avoids Cremophor EL and reduces hypersensitivity risk?
- Nab‑paclitaxel (albumin-bound paclitaxel, Abraxane)
- Taxol with extra ethanol
- Paclitaxel in PVC solution
- Paclitaxel powder for oral tablets
Correct Answer: Nab‑paclitaxel (albumin-bound paclitaxel, Abraxane)
Q18. Paclitaxel primarily binds to which tubulin subunit?
- β‑tubulin
- α‑tubulin
- γ‑tubulin
- Delta tubulin
Correct Answer: β‑tubulin
Q19. Paclitaxel causes cell cycle arrest at which phase?
- G2/M phase
- G0 phase
- S phase
- G1 phase
Correct Answer: G2/M phase
Q20. Standard premedication to reduce paclitaxel-induced hypersensitivity includes:
- Corticosteroids and antihistamines
- ACE inhibitors and beta blockers
- Broad-spectrum antibiotics
- Antacids only
Correct Answer: Corticosteroids and antihistamines
Q21. When administering Cremophor EL–based paclitaxel, what infusion practice is recommended?
- Use non‑PVC administration sets to avoid leaching
- Infuse through PVC tubing only
- Expose to direct sunlight during infusion
- Use glucose 50% in all dilutions
Correct Answer: Use non‑PVC administration sets to avoid leaching
Q22. Which alternative sustainable source has been explored for paclitaxel production?
- Endophytic fungi producing paclitaxel
- Cattle serum fermentation
- Seaweed photosynthesis
- Synthetic rubber derivatives
Correct Answer: Endophytic fungi producing paclitaxel
Q23. In HPLC analysis for paclitaxel, which parameter indicates identity confirmation?
- Matching retention time with an authentic standard
- Color of the sample vial
- pH of mobile phase only
- Length of the HPLC column alone
Correct Answer: Matching retention time with an authentic standard
Q24. The therapeutic index of paclitaxel is generally considered:
- Narrow, requiring careful dosing and monitoring
- Very wide and forgiving for dosing errors
- Irrelevant for chemotherapeutic drugs
- Predictable by body temperature alone
Correct Answer: Narrow, requiring careful dosing and monitoring
Q25. Paclitaxel’s effect on tubulin polymerization is to:
- Promote and stabilize polymerization into microtubules
- Prevent tubulin from polymerizing at all
- Disrupt actin filaments only
- Cleave tubulin into peptides
Correct Answer: Promote and stabilize polymerization into microtubules
Q26. Major route of elimination for paclitaxel is:
- Hepatic metabolism with biliary excretion
- Renal excretion as unchanged drug predominantly
- Exhalation in expired air
- Sweat excretion primarily
Correct Answer: Hepatic metabolism with biliary excretion
Q27. Paclitaxel use during pregnancy is classified as:
- Contraindicated due to potential teratogenicity
- Safe and recommended in first trimester
- Recommended as a vitamin supplement
- Approved for routine obstetric use
Correct Answer: Contraindicated due to potential teratogenicity
Q28. Combining paclitaxel with other highly myelosuppressive agents will most likely:
- Increase the risk and severity of neutropenia
- Completely prevent neuropathy
- Reduce the antitumor efficacy significantly
- Eliminate the need for dose adjustments
Correct Answer: Increase the risk and severity of neutropenia
Q29. A key industrial challenge in paclitaxel manufacturing is:
- Low natural abundance of precursor and complex purification needs
- Excessively high precursor availability making quality control trivial
- No regulatory oversight required for plant-derived drugs
- Instantaneous scale-up with no process validation
Correct Answer: Low natural abundance of precursor and complex purification needs
Q30. For sustainable process development of Taxol, which approach is considered green chemistry?
- Semisynthesis from renewable needle-derived precursors and biocatalysis
- Increasing bark harvesting without replanting
- Using large volumes of chlorinated solvents with no recycling
- Discarding waste streams directly into waterways
Correct Answer: Semisynthesis from renewable needle-derived precursors and biocatalysis
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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