Allergy Medication Trial

In this study researchers want to learn how quickly patients suffering from allergic rhinitis (also known as hay fever) can expect symptom relief after using Azelastine Hydrochloride 0.15% Nasal Spray. This study plans to enrol about 80 male or female participants in the age of 18 to 65 years suffering from an allergic rhinitis to ragweed pollen for at least 2 years. In a first phase participants will be exposed to ragweed pollen in a special study room to ensure they will be adequately symptomatic when they progress into the treatment phase of the study. In a second phase study participants will be divided in 2 groups. After exposure to ragweed pollen one group will receive Azelastine Hydrochloride 0.15% Nasal Spray and the other group will receive placebo (a nasal spray which does not contain any active drug substance). In the third phase of study the treatment will be switched: participants who received in the previous study Azelastine Hydrochloride 0.15% Nasal Spray will receive the nasal spray without any active drug substance and the other group will receive Azelastine Hydrochloride 0.15% Nasal Spray. During the second and third study phase the researchers will examine thoroughly over 4 hours the change of nasal symptoms such as runny nose, itchy nose, sneezing and nasal congestion after participants received the nasal spray.