Analytical Approach for the Optimization of Desiccant Weight in Rapid Test Kit Packaging: Accelerated Predictive Stability (APS)
Prince Manta, Pritt Verma, Louis Cojandaraj , Shruti Singh, Akanksha Pangotra, Shravan Kumar Paswan, Deepak N Kapoor
Present study involved determining the weight of cobalt-free desiccant (non-indicating) required in order to maintain the pregnancy test kit functionalityduring accelerated stability studies. The desiccant sachets were placed inside the aluminum pack to prevent damage to the immune chromatographic kits from humidity. The most of immune chromatographic test kits use indicating silica gel as a desiccant. The weight of silica gel in test kits ranges from 0.5 gm to 1.0 gm,which wasused indiscriminately by manufacturers without any scientific rationality. The WHO has recommended verifying the desiccant condition before utilizing malaria test kits for diagnosis to identify the damageto the device. The non-indicating silicagel has the advantage of being cobalt-free, which is nontoxic. In comparison, non-indicating silica gel has the disadvantage of being unable to be identified by color change when packaging has leakage for ambient moisture, causing damage to the kit. The immune chromatographic test kits use antigen-antibody proteins for functioning, which are conjugated with a marker and coated on control and test line. High humidity can alter the functionality of proteins, conjugation, and affect the efficacy and efficiency (sensitivity and specificity) of the kits during the shelf life. Currently, the evidence of desiccants impact on kit stability is very minimal. Herein, we found that Weintraub and Tetreault's equation is the best method for calculating the optimum weightrequired for non-indicating silica gel. Utilizing this equation 1.5 gm of silica gel is the ideal weight required to sustain the sensitivity of the pregnancy test kit in 300C + 20C (temperature) and 75 % + 5 % (relative humidity) over 180 days in accelerated condition.