Inspired interim responses to hitherto unknown problems, New Deal economic stratagems became (i) _______ as a result of bureaucratization, their flexibility and adaptability destroyed by their transformation into rigid policies.

The New Deal economic strategems became something as a result of bureaucratization and the destruction of their flexibility and adaptability. And they were transformed into rigid policies.

I am looking for a synonym for becoming rigid and inflexible. Ossified is the correct word. Ossified means to stop developing and become stagnant. Literally to become ossified means to turn into bone or bony tissue (which is hard and inflexible)

bureaucratization - adherence to rigid procedures and controls.