Validation of an in vivo technique for quality assessment of ^99mTc-HSA nanocolloid kit and its shelf-life extension

Particle size distribution (PSD) followed by % radiochemical purity (%RCP) assessment is the currently employed quality control (QC) measure to assess suitability of HSA-nanocolloid kit used in SLN detection. However, it would be advantageous to have a standby protocol in case of breakdown or unavailability of PSD measurement. Therefore, we validated (as per the Radiopharmaceuticals Committee (RPC) guidelines) a previously reported footpad method in rat model, which is based on physiological distribution (PD) studies of the formulation, as an alternate QC protocol. Furthermore, the current shelf-life of this product supplied from BRIT is only 2 months thereby limiting its convenience at both manufacturers as well as at user end. Using this method to complement existing QC protocol, investigations were conducted to ascertain the possibility of increasing shelf-life of this kit. PD studies have been validated as an alternate QC method to particle size distribution of HSA-nanocolloid kit used in SLN detection. Based on our stability studies, the shelf-life of the kit has been extended to 4 months. Both of them have been approved by RPC