How to set specifications Examination of the ICH guidelines for residual solvents

The introduction briefly summarizes the strategies dealing with the setting of specifications in pharmaceuticals which appeared during the 80 s. 

From the early 90 s onwards, the International Conference on Harmonization was initiated in three important pharmaceutical regions (Europe, Japan, USA) in order to define a common way of preparing a registration file acceptable in the three zones. The topics included in this harmonization process are  

Regarding Quality a set of Guidelines have been already adopted. Three of fliem are particularly relevant with regard to this article  

Comments on the latter are given below. The full text can be found in the US Pharma-eopoeia, in the European Pharmaeopoeia or in Journals (there is also a website -www.ifpma.org/ichl. htm). 

The Guideline recommends acceptable amounts of RS in pharmaceuticals which are safe for the patient. Residual solvents in pharmaceuticals are defined as organic volatile chemicals that are used or produced in the manufacture of active substances or excipients, or in the preparation of medicinal products. It is stated that medicinal products should contain no higher levels of residual solvents than can be supported by safety data. Three classes of solvents have been defined based on risk assessment. 

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