Okla. Stat. tit. 36, § 5403

Manufacturers - Interference with acquisition or delivery prohibited. A. A manufacturer shall not deny, restrict, prohibit, or otherwise interfere with, either directly or indirectly, the acquisition of a 340B drug by, or delivery of a 340B drug to a 340B entity, unless such receipt is prohibited by the United States Department of Health and Human Services. B. A manufacturer shall not interfere with a pharmacy contracted with a 340B entity. C. A 340B entity shall contract with any willing pharmacy upon mutually agreeable terms within a fifteen-mile radius of the 340B entity's location. D. Nothing in this section shall be construed to limit the number of pharmacies that a 340B entity shall be allowed to contract with.