He began his career at the Arab Pharmaceutical Industries from 1994 to 2000, then served as the Director of Research and Development at the Jordanian-Swedish Pharmaceutical Company in 2007. Dr. Najjar left the Swedish company to establish Sana Pharma, the first pharmaceutical research company in Jordan, with a group of specialists in the pharmaceutical industry.
Dr. Najjar has contributed to numerous research studies published in international pharmaceutical journals. He has also been involved in two patented inventions registered in the United States: one concerning the treatment of resistant hypertension by focusing on the "circadian rhythm" system, and the other involving a new biological drug for treating specific types of cancer.
Sana Pharma began developing drugs, undertaking technology transfer projects, and providing pharmaceutical analysis services in 2008 after obtaining international accreditation as a reference and peer-reviewed laboratory. The company's projects have extended to more than 24 countries in the Middle East, North Africa, and Europe.
In 2015, Sana Pharma became a manufacturer of pharmaceuticals and medical supplies, specializing in the development, manufacturing, and marketing of specialized pharmaceutical products with added value.