The purpose of this research study is to test the safety, tolerability, and effectiveness of Topical AmphiMatrix with Nitroglycerin (MQX0503) to relieve Raynaud's symptoms and increase blood flow to the fingers.

The purpose of this clinical study is to determine, in a controlled fashion, the ability of a topical formulation of Nitroglycerin, MQX-503, to improve the patient's health assessment as indicated by patient and physician assessments, decrease the frequency of Raynaud's events, decrease the duration of Raynaud's events, and decrease the symptoms (pain, tingling, numbness) in the fingers of Raynaud's patients. The study will include patients with moderate to severe primary Raynaud's Phenomenon (RP) and with moderate to severe Raynaud's Phenomenon secondary to autoimmune diseases, such as scleroderma.

Inclusion Criteria:

• Outpatients ages 15 - 70.
• Patients with a diagnosis of Raynaud's phenomenon.
• Patients who agree to apply study medication to their fingers.
• Patients who are willing to stop current topical vasodilator therapies.
• Patients who agree not to start or change dosage of current oral vasodilator therapies.
• Patients who agree not to use any nitrate therapy while participating in this study.
• Negative pregnancy test in fertile women and agreement to use effective contraception throughout the study.

Exclusion Criteria:

• Patients who currently use nitrate medication or medications known to interact with nitroglycerin.
• Patients who have an allergy to nitroglycerin or common topical gel ingredients.
• Patients with a history of severe headaches.
• Patients with an unstable medical problem.
• Patients with cognitive or language difficulties that would impair their ability to complete assessment of pain instruments.
• Patients who have had a recent heart attack or other uncontrolled heart condition.
• Patients who have participated in an investigational drug study within four weeks of visit one.
• Patients who have clinically significant abnormal lab values.
• Patients who have had recent major abdominal, thoracic or vascular surgery.
• Patients with interfering skin conditions.
• Pregnant or nursing women or women unwilling to comply with contraceptive requirements.