Storage Stability Trials for Agrochemicals
When formulations are moved into a new system, they often become unstable. For a stable solid containing agrochemicals formulations, a stable solid can be delivered with or without a liquid phase. The formulation is diluted with water to form a suspension, emulsion or solution, which is then applied to the plant. For the application of plants, the final agrochemical product molecules must be dissolved and penetrate into the cells. The physical stability of each agrochemical formulation is critical since a more stringent control of temperature conditions is required. BOC Sciences conducts a rational investigation of the physical stability of model systems to offer rational decisions regarding formulation systems. Therefore, our experts perform extended storage stability testings during formulation development, thereby accelerating the development of formulation forms for agrochemicals.
Figure 1. Controlled release of agrochemicals using pH. (Hou, X.; et al. 2019)
Accelerated Storage Testing
Stability testing at high temperatures is performed to increase the rate of chemical degradation or physical changes in an agrochemical product in order to obtain information on the shelf-life in a shorter period of time than a real-time study. Accelerated testing involves extrapolation from higher to lower temperatures, and from shorter to longer storage periods.
Real-time Testing
Data from accelerated stability studies can provide a useful indication of the stability of an agrochemical product's stability. However, for agrochemical products that require a tendency to cake over time, real-time testing data is also critical.
- At BOC Sciences, real-time testing is typically performed at or above 25 ˚C with storage for at least 2 years. Moreover, testings are performed at time zero and at the end of the storage period.
- Depending on the type of product formulation and packaging material, our team uses standardized relative humidity and light conditions.
Low Temperature Storage Stability Testing
In general, liquid formulations such as capsule suspensions, emulsified concentrates, oil-in-water emulsions, microemulsions, soluble concentrates and suspension concentrates may be adversely affected by storage at low temperatures, resulting in crystallization of the active ingredient, significant changes in viscosity and/or phase separation of the emulsion.
- Therefore, liquid formulations should be tested at 0˚C ± 2˚C or lower, for 7 days, and the effect of low temperatures on stability is determined and reported.
- For capsule suspension formulations, we perform freeze-thaw cycling tests as the capsule walls may break as a result of repeated freezing and thawing.
Ambient Storage Stability Testing
- Ambient storage stability is typically conducted with storage under ambient warehouse conditions for 2 years, with analysis of product at initial timepoint and then after 6, 12 and 24 months storage.
- We can design the experiments according to your requirements for any duration and frequency of timepoints.
BOC Sciences Advantages
- Highly specialized technical and analytical services for the worldwide registration and regulatory compliance of agrochemicals
- Robust analytical testing programs that span from research and product development through the production process to final product
- Relies on broad industrial experience, ensuring that all of our work meets the high standards expected by our clients
- Our regulatory experts, toxicology consultants, scientists and inspectors will ensure that you receive maximum levels of guidance, testing and inspection you need.
Reference
- Hou, X.; et al. Controlled Release of Agrochemicals Using pH and Redox Dual-Responsive Cellulose Nanogels. Journal of Agricultural and Food Chemistry. 2019. 67(24).