The invention provides a composition containing particulate composite of a polymer and a therapeutic agent. The composition also contains a complexing agent. The polymer interacts with the complexing agent in a host-guest or a guest-host interaction to form an inclusion complex. A therapeutic composition of the invention may be used to deliver the therapeutic agent and to treat various disorders. Both the polymer of the particulate composite and the complexing agent may be used to introduce functionality into the therapeutic composition. The invention also relates to a method of preparing a composition. The method combines a therapeutic agent, a polymer having host or guest functionality, and a complexing agent having guest or host functionality to form the therapeutic composition. The complexing agent forms an inclusion complex with the polymer. The invention also relates to a method of delivering a therapeutic agent. According to the method, a therapeutically effective amount of a therapeutic composition of the invention is administered to a mammal (e.g. person or animal) in recognized need of the therapeutic. Also disclosed are compounds having the formula: