Preservatives in liquid pharmaceutical preparations

Sodium benzoate, potassium sorbate, and methyl hydroxybenzoate are com- monly used as preservatives in liquid pharmaceutical preparations. The pur- pose of this study is to determine the amount of the aforementioned preserva- tives in pharmaceutical products, as some recent studies have reported seri- ous side effects associated with the ingestion of these substances. The con- tent of 37 liquid pharmaceutical prod- ucts were simultaneously determined by high performance liquid chromatogra- phy. Preparations were analyzed in trip- licate for their preservative content using a sensitive and reproducible HPLC method modified in our laborato- ry. Preservative levels were found to fall outside the typical allowed concentra- tion range for 70% of the samples, with some exhibiting significantly higher con- centrations. The reason behind such findings is unclear, and could be due to poor quality control or to intentionally extend the shelf-life of the products. These findings highlight issues related to quality control and to patient's safety. Consequences on patient health need to be evaluated, especially since most liq-