Filing in this space is concentrated: the top 5 ranked assignees hold 280 of the 778 records in scope, or 36.0% of the total, and the top 10 combined hold 463 records, or 59.5%. The single leading assignee holds 87 records, well ahead of the fifth-ranked filer at 42 and the tenth-ranked filer at 33. Below the top ten, the field fragments into a long tail of assignees with only a handful of filings each, which is typical of a formulation-adjacent technology where many pharmaceutical and specialty-chemical companies file occasionally rather than systematically.

Filing peaked at 28 records in 2017 and has declined since; the 2021-to-2024 window shows an 80% drop, from 5 filings down to 1. That said, publication lags actual filing by roughly 18 months, so the 2025 and 2026 figures in any dataset are still incomplete and should not be treated as confirming a continued decline. The safest reading is that activity has cooled from its mid-2010s peak, with the most recent trend still an open question.

Pharmaceutical formulation classes dominate: A61K (medicinal preparations) appears on 47.4% of the 778 records, and A61P (therapeutic activity of compounds) on 18.1%. The core process class B01J (chemical and physical processes) sits at 24.6%, while the dedicated drying class F26B appears on just 4.6% of records. This tells you the corpus is built more around what is being formulated and dried than around dryer apparatus design itself, which matters when benchmarking equipment novelty.