Respiratory, allergy and digestive drugs

Many of these APIs go into over-the-counter products, so volumes are high and price competition is strong. Inhaled drugs are a special case. They need micronised material with tightly controlled particle size distribution and often a pharmaceutical lactose carrier, and they are bought in small quantities with extensive characterisation.

Specify the salt and hydrate form, particle size where relevant, related substances, residual solvents and the pharmacopoeia grade. Proton pump inhibitors are unstable in acid and moisture, so packaging and storage conditions matter. Some cough and cold actives, such as pseudoephedrine and ephedrine, are controlled precursors, and their trade needs licences and end-use declarations in most countries.