Introductory trade or stock packages may be distributed by registered drug manufacturers to licensed pharmacies under the following conditions:

(1) The package shall be invoiced by the drug manufacturer as a no charge sale.

(2) The product shall be distributed by the manufacturer to the pharmacy by mail or common carrier.

(3) The drug's package shall not be marked as a sample or with any other labeling that is inconsistent with the claim that the manufacturer intended the package for sale.

(4) The manufacturer shall be limited to distributing one introductory package of each dosage strength of a product on a one-time basis to a pharmacy in order to familiarize and assure that a company's new product will be available in pharmacies. The quantity shall not be larger than one hundred solid dosage units or sixteen liquid ounces.