The Health Sciences Authority (HSA) Singapore has published a document on the common questions received for Generic Drug Applications in September 2021. The document highlights some questions and answers relating to Bioequivalence (BE) study requirements and Singapore Reference Product (SRP).
In cases where an SRP is no longer registered or marketed, applicants may choose to use an alternate registered comparator product if adequately justified. For example, if a registered generic therapeutic product is widely used by local hospitals, that would be acceptable by HSA. However, the acceptability of the justification will be determined during the screening stage of the application. Sections 16.1 and 16.2 of the Guidance on Therapeutic Product Registration in Singapore can be used as a reference for further clarification on SRP.
Regarding BE study design, if an applicant wishes to apply for a certain drug in a particular strength but the BE study conducted is with a higher strength, this is acceptable. However, the biowaiver criteria for the additional (non-study) strengths must be fulfilled. The ASEAN Guideline for the Conduct of Bioequivalence Studies can be used as a reference and the relevant section is 3.1.6.
HSA has also included some information on biowaivers, whereby the ICH M9 Guideline (Biopharmaceutics Classification System (BCS)-based Biowaivers) is the main reference document and has details regarding BCS classification of drug substances.
More details can be found in “Common Questions related to generic drug applications”, September 2021: https://www.hsa.gov.sg/therapeutic-products/register/guides/generic-drug/common-questions-related-to-GDA