Quorum Sensing Inhibitor from the Bark of Pithecellobium dulce (Kamatsile) and the process of making thereof. The present invention relates to a composition for anti-pathogenic drugs more particularly to quorum sensing inhibitor syrup from the semi-purified tannins of Pithecellobium dulce (kamatsile) bark. The increased prevalence of antibiotic-resistant bacteria due to the extensive use of antibiotics has rendered the current antimicrobial agents inefficient to control several bacterial diseases. Many opportunistic pathogenic bacteria depend on QS systems to coordinate their virulence expression. Thus, interference with QS has been regarded as the novel way to control bacterial infections. One of the measures to combat this problem is to have continuous investigations into new, safe and effective alternative agents to substitute the present less effective ones. Plants have been traditionally proven to be a rich source of novel drug compounds and its herbal mixtures have made a large contribution to human health and well being. Thus, it becomes necessary to analyze the vast untapped potential of the medicinal plants in combating the antibiotic resistant organisms.