Under what circumstance can a pharmacy legally distribute controlled substances to a practitioner?

A pharmacy can legally distribute controlled substances to a practitioner when the practitioner is registered and there is proper documentation of the distribution. This requirement is in place to ensure that there is a legitimate purpose for the transaction and that it adheres to regulations governing controlled substances.

The practitioner's registration is crucial because it indicates that the practitioner is authorized by the Drug Enforcement Administration (DEA) to handle controlled substances. Additionally, documenting the distribution serves as a safeguard to maintain accurate records and accountability, which is a fundamental aspect of controlled substance regulations. This process helps prevent misuse or diversion of these substances and ensures compliance with the legal framework surrounding their distribution.

In contrast, the other options would not align with the legal requirements. Competing pharmacies, verbal transactions, or expired substances do not meet the necessary legal standards for the distribution of controlled substances. Therefore, only the option pertaining to the practitioner being registered and maintaining documentation aligns with the legal framework outlined for the distribution of controlled substances.