The Q3D Guideline has reached Step 4 of the ICH process in December 2014.

This guidance aims to provide a global policy for limiting metal impurities qualitatively and quantitatively in drug products and ingredients. The existing ICH Q3A Guideline classifies impurities as organic, inorganic, and residual solvents. The Q3A and Q3B Guidelines effectively address the requirements for organic impurities. An additional Guideline Q3C was developed to provide clarification of the requirements for residual solvents. The proposed new Guideline Q3D would provide similar clarification of the requirements for metals, which are included in the ICH inorganic impurities classification.

该指南目的是提供一份全球方针来定性和定量限制药品和药品组份中金属杂质。已有ICH Q3A指南将杂质分类为有机杂质、无机杂质和残留溶剂。Q3A和Q3B指南有效地说明了对有机杂质的要求，Q3C阐明了残留溶剂的要求。新指南Q3D将对金属提供类似的说明，金属包括在ICH无机杂质中。