Some artificial salivas scott mentioned are: Oasis, Biotene, and Salivart
All are OTC and can be found in any store with a pharmacy.
Please google xerostomia, you probably can get detailed information.Seeing an oral medicine specialist to identify the cause of xerosomia is advised.In the mean time, you can purchase artificial saliva to relieve your symptom.It's geerally OTC, you can purchase without prescription.