(a) General. A person who engages in the wholesale distribution of prescription drugs in this state for use in humans is exempt from this subchapter if the person is exempt under:(1) the Prescription Drug Marketing Act of 1987 (PDMA Act), (21 United States Code (USC) §353(c)(3)(B));(2) the regulations adopted by the secretary to administer and enforce the PDMA Act;(3) the interpretations of the PDMA Act set forth in the compliance policy manual of the United States Food and Drug Administration; or(4) the Texas Occupations Code §562.154.(b) Exemptions from licensing. Persons who engage in the following types of distribution of prescription drugs are exempt from the licensing requirements of this subchapter, to the extent it does not violate provisions of the Texas Controlled Substances Act, Texas Health and Safety Code Chapter 481, or the Texas Dangerous Drug Act, Texas Health and Safety Code Chapter 483:(1) intracompany sales of prescription drugs, which means transactions or transfers of prescription drugs between a division, subsidiary, parent, or affiliated or related company under common ownership and control, or any transaction or transfer between co-license holders of a co-licensed product;(2) the sale, purchase, trade, or transfer of prescription drugs or the offer to sell, purchase, trade, or transfer a prescription drug for emergency medical reasons; including a transfer of a prescription drug by a retail pharmacy to another retail pharmacy to alleviate a temporary shortage;(3) the distribution of prescription drug samples by a representative of a manufacturer;(4) the return of drugs by a hospital, health care entity, or charitable institution in accordance with