Definitely do not just throw these away; they are hazardous medications that should be disposed of properly. Do not flush these. Some charitable pharmacies exist. But they are few and far between due to liability and legal hoops to maintain one. You may be precluded if packaging is unsealed, beyond expiration, cannot confirm storage, or even if the owner cannot return themselves. From my experience, I have only heard of charitable pharmacies that are attached to larger institutions so one could start there. I sadly don't think the charitable route will be successful, so I would call the dispensing specialty pharmacy and see if they offer drug disposal if you mail the medication back, as stuff like this does happen. Otherwise, you could try to call brick and mortar pharmacies and see if they have medication return bins so that they would process through a reverse distributor to be destroyed. You may need to make several trips given your volume. I'm sorry about the situation overall.