User blog comment:Espada2011/Aizen's power/@comment-11051098-20140404183121

Urahara said the Hôgyoku abandoned Aizen because it didn't consider him its master anymore, most likely because a "mere human" overpowered and defeated him. What if the Hôgyoku also caused his blade to dissolve because it considered him unworthy of having a Zanpakutô and its power because he used this power for evil doings?

If so, it would be strange that it accepted him as its master in the first place, but maybe it was waiting for someone strong enough to defeat Aizen.

I don't know if this has been answered in any way.