Doxycycline is used for malaria prophylaxis or treatment. When it is administered for treatment of P falciparum malaria, this drug must be used as part of combination therapy (eg, typically with quinine or quinidine).
If you buy goods and are not charged the Rhode Island Sales Tax by the retailer, such as with online and out-of-state purchases, you are supposed to pay the 7% sales tax (less any foreign sales tax paid) for these items yourself as the Rhode Island Use Tax.
Department of Taxation and Finance. Sales and use tax. Sales tax applies to retail sales of certain tangible personal property and services. Use tax applies if you buy tangible personal property and services outside the state and use it within New York State. Video: NYS Sales Tax. Starting a Business.