Toxic materials, safety design reviews

Established excipients pose some issues for regulatory consideration. Such issues include the use of a well known excipient by an unapproved route, for example, inhalation of a material that has been used in oral formulations. In these cases, some preliminary toxicity studies may be necessary. Additionally, a well designed scientific review of safety data on the excipient will be necessary, with old findings fully evaluated. 

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