Safety and Tolerability of a nasal spray in patients with Chronic allergic or nonallergic rhinitis

This study is testing a new nasal spray called MP03-33 over a full year to see if it is safe and well-tolerated in people who have long-term nasal allergy symptoms or non-allergic runny nose and congestion. These symptoms can be caused by dust mites, pet dander, or other triggers that affect people year-round. An existing approved nasal spray (azelastine) will be used as a comparison. Participants will use the spray daily for 12 months, and their safety will be monitored throughout. You may be eligible if: - You are 12 years of age or older - You have had nasal allergy symptoms or non-allergic rhinitis for more than 1 year - Your symptoms occur year-round (not only during a specific pollen season) - You are in generally good health - You are able and willing to use the nasal spray every day for 12 months You may NOT be eligible if: - You are pregnant or breastfeeding - You are a woman of childbearing age who is not using reliable contraception - You are allergic to azelastine or to sorbitol or sucralose - You have nasal polyps, chronic sinusitis, or a significant structural problem in your nose - You have moderate to severe asthma or a major lung condition - You have a history of alcohol or drug abuse Talk to your doctor about whether this trial might be right for you.