Padlocks are not recommended especially for full TLs as they can be opened without knowledge multiple times. Drivers should have seals with them for multiple drops but there's no way to gurantee the product once the first seal is broken anyway.
A “belt and braces” approach with a new seal every drop is more likely appropriate to food. As with anything it would depend on what you are transporting and what is the risk. This topic is for packaging: FSC 27 Manufacture of Food Packaging - Example of Products:
All food-grade packaging materials, including flexible films, paperboard- based containers, metal containers, flexible pouches, glass containers, plastic and foam containers (PET, polystyrene, etc.), and single-use foodservice products (e.g., paper towels, napkins, disposable food containers, straws, stirrers).
If the packaging is packaged such that any tampering would evident and the vehicle is not going to be left unattended then putting a high-level security padlock on the vehicle for multiple drops would be acceptable IMO.