How many controlled substances can be stored in a matrix drawer of an ADS at one time?

In an automatic dispensing system (ADS), regulations dictate the conditions under which controlled substances can be stored. The correct answer indicates that only one controlled substance can be stored in a matrix drawer at one time, while all remaining medications in that drawer must be non-controlled substances. This regulation is in place to help maintain security and oversight of controlled substances, which are more susceptible to misuse and diversion compared to non-controlled medications.

Limiting the number of controlled substances in a storage area reduces the risk of confusion among pharmacy staff and minimizes the potential for theft or diversion. It also enhances the accountability and accuracy of inventory management for controlled substances.

The other options suggest scenarios that either do not comply with the regulations governing ADS use in pharmacies or misrepresent the requirements for what can be stored in a matrix drawer. For instance, allowing two controlled substances without limitations increases the risk of error and mismanagement, while asserting there is no limit contradicts the intent of stringent regulations surrounding the storage of controlled substances. Therefore, the specified limit of one controlled substance with the stipulation of all remaining inventory being non-controlled is both practical and regulatory compliant.