Concerns have emerged recently from companies using Tromethamine, Tris Hydrochloride or Tris (Base) in their drug manufacturing processes due to issues caused by formaldehyde/para-formaldehyde contamination found in their products due to issues caused by formaldehyde/para-formaldehyde contamination found in the products that were sourced from certain areas of China.
Tris is made by reacting formaldehyde with Nitromethane to prepare an intermediate (HOCH2)3CNO2. Reduction of the latter produces Tris. Formaldehyde comes in a water solution where formaldehyde may polymerize to Para-Formaldehyde, often found as crystals in the solution. As a result, Para-Formaldehyde is a common impurity in crude Tris. Para-Formaldehyde undergoes de-polymerization that gives formaldehyde.
It has been reported that testing a 1M solution with UV at 260 nm, 280 nm and 400 nm will detect any absorbing species, such as aromatics and double bound compounds that could present problems for certain biotech applications. Possible degradation products might be formaldehyde, methanol and ammonia. The UV scan will pick up aldehydes, ketones and carboxylic/amino acids.
Rx-360 member Mallinckrodt Baker has developed a UV method to screen Tromethamine, Tris Hydrochloride or Tris (Base) and will be making the method available shortly to the Rx-360 community. When the method is available, it will be released with a Rx-360 Flash Report.