Chlortetracycline (Aureomycin) exhibits greatest solubility in which of the following?

Introduction / Context:
Tetracyclines are amphoteric compounds whose solubility depends on pH and solvent polarity. Chlortetracycline is classically described as sparingly soluble in water but more soluble in several polar organic solvents used in extraction and purification steps.

Given Data / Assumptions:

• We compare general solubility trends relevant to recovery/purification.
• Ether is far less effective than alcohols/ketones for dissolving chlortetracycline.

Concept / Approach:
Chlortetracycline dissolves better in certain organic solvents (e.g., methanol, ethanol, acetone) than in neutral water. Water solubility is limited and pH-dependent; ether is generally a poor solvent for such polar amphoteric antibiotics. Thus, among the choices, “organic solvents” best describes practice in downstream processing.

Step-by-Step Solution:

Verification / Alternative check:
Pharmacopoeial and process references list limited aqueous solubility and improved solubility in alcohols/acetone for chlortetracycline.

Why Other Options Are Wrong:

• Water: only sparingly soluble; statement overstates solubility.
• Ether: poor solvent for this compound class.
• All of these/none: contradict empirical recovery protocols.

Common Pitfalls:
Assuming all antibiotics with polar groups are highly water-soluble at neutral pH; ionization state matters.

Final Answer:
Organic solvents (e.g., alcohols), more than in water