Regulators and industry are exploring more deeply the complex web of issues involved with effective use of preservatives in drug products, as the challenges and the consequences come into clearer view.
Factors included in this web are: ● product formulation ● manufacturing process control, the quality of materials, the safety concerns that preservatives pose, the unique characteristics of various bacteria, the relative strengths and weakness of the available preservatives and their use in combination, and how the products are packaged and handled by the users.
At the May 2019 IPEC-Americas’ Excipient World conference held in National Harbor, Maryland, Unicus Pharmaceutical Consultant Nelson Ayala brought his extensive formulation experience and additional recent academic study in microbiology and genetics to bear in a presentation on the current challenges of effective preservative usage in the context of the complex interactions among the many factors involved.
Ayola’s insights are broadly engaging, but particularly valuable for those with responsibility for assuring that contamination risks are understood and addressed.
He began his presentation by reviewing the evolution, lifecycle, and growth factors of the most common bacteria of concern, including Escherichia coli (E.coli) and Staphylococcus aureus. He then offered insights on: ● preservatives, bacteria and their interactions ● product-specific attributes – particularly water content, and ● key preservatives and their effectiveness.