QR-441

QR-441 (also referred to as QR-441(a)) is an experimental broad-spectrum antiviral compound developed by Quigley Pharma for veterinary applications. It was primarily investigated as a natural antiviral agent for the prevention and treatment of viral diseases in livestock and companion animals. In 2005, the FDA's Center for Veterinary Medicine granted nine Investigational New Animal Drug (INAD) numbers for the compound, targeting the H5N1 avian influenza virus across multiple species (including poultry, swine, equine, and canine) and canine arthritis. Research indicated potential efficacy against Infectious Bronchitis and Newcastle Disease in poultry. The drug was evaluated in various delivery formats, including medicated feed, water, and intranasal administration, and demonstrated a favorable safety profile in avian studies.