Sydenham Laboratories, Inc. (SLI)  is an ISO 9001:2008, HACCP Certified, PIC/s GMP compliant pharmaceutical company that develops and manufactures healthcare products. SLI manufactures oral drug preparations in dosage forms of tablet, capsule, syrup, and powder for suspension. Non-penicillin, penicillin and cephalexin-based products are manufactured in separate buildings with 'clean room hepa-filtered' exclusive air-handling systems to ensure zero-cross contamination. SLI also manufactures food supplements in the above dosage forms. 

SLI is founded in 1971 by Dr. Eduardo R. dela Cruz, MD, a cardiologist and a former president of Philippine Medical Association.

SLI derived its name from one of the great British physicians, Dr. Thomas Sydenham, known as the English Hippocrates, the founder of clinical medicine, and an advocate of effective management of illness that emphasized detailed observation and maintained patient records.