Chlorsol 50% Powder for oral solution Pharmaceutical precautions Once opened, the entire contents of the 200g sachet must be added to the required quantity of water. After opening the inner sachet of a 2kg pack, seal after use and keep container tightly closed. Once inner sachet has been opened, contents must be used within 7 days. Any medicated water which is not consumed within 24 hours should be discarded safely. Absorption of chlortetracycline from the alimentary tract is reduced by calcium, iron, magnesium and zinc salts. Do not store above 25°C. Store in a dry place. Unused product or waste material should be disposed of in accordance with national requirements