Liquid Oral Dosage Forms

Liquid Oral Dosage Forms

Oral liquids are homogeneous liquid formulations containing one or more active substances in a liquid foundation. They are used orally as is or diluted and may contain authorized sweeteners, flavorings, and colorings. There are several varieties of liquid oral dose forms including syrups, suspensions, solutions, drops, emulsions, mixtures, linctuses, and elixirs.

Liquid oral dose forms, including solutions and suspensions, offer a low packaging risk according to global authorities. The FDA’s 1999 Container Closure Guideline gives oral solutions and suspensions a moderate level of packaging interaction concern due to the high possibility of a packaging-dosage form interaction and the lowest route of administration concern. USP <1664> also confirms moderate risk. Furthermore, the European Medicines Agency (EMEA) Immediate Packaging Guidelines state that packaging methods for liquid oral dosage forms and their materials may need extensive testing, including extraction, migration, and toxicological investigations, to ensure safety. 

It is challenging to generalize about how to design and implement extractable and leachable studies for liquid oral dosage forms due to their wide variety of formulations, packaging techniques, and clinical uses. Aqueous drug products, low daily dose volumes, and acute clinical usage may allow direct screening for leachable at levels approaching relevant reporting thresholds. In more complex circumstances, extraction studies (particularly simulation studies) may be necessary for safe use assessment.

Successful and practical extractable and leachable assessments for liquid oral dosage forms require strategic planning, study design, study execution, and a deep understanding of materials, extractable, and leachables. Experienced analytical scientists and study directors are essential for chemical testing programs using cutting-edge analytical methods and to help drug product and packaging manufacturers and vendors get regulatory approval for their products.

Video 01: Oral Liquid Dosage Forms