Sigjohn Pharmaceuticals was established as a single proprietorship in 1985, a pharmaceutical drug trader with an initial capital of Php 50,000.00. Three years after being established, the company was officially registered as private corporation with a capital stock of Php 1,000,000.00 under the management of Ms. Zenaida C. Yap, Mr. Agustin Chuatoco, Mr. Leopoldo Chuatoco and Mr. Edgardo Chuatoco. Duly accredited by the Department of Health (DOH) and Bureau of Food & Drugs (BFAD), it is one of the main marketing arm of San Marino Laboratories Corporation - a manufacturer of quality pharmaceuticals and patented household drugs and specialties.

Among the company's clientele include various institutions and industrial companies (Iglesia ni Kristo, Benguet Mining, Sony, German Doctors - a foundation formed by German Nationals, etc.), various municipalitites and local government (Dinalupihan, Bataan; Cabuyao, Laguna; Paete, Laguna; Sto. Tomas, Batangas; Alitagtag, Batangas; etc.), Mercury Drug provinical outlets, drugstores, private and public hospitals and doctors.

Sigjohn Pharmaceuticals started with only four products to offer in the market such as Dicycloverine, Guaifenesin, Ampicillin and Penicillin. Even with only a few products to offer, the company established a niche in the market and felt the need of hiring additional sales representatives to cover the whole of Metro Manila and nearby provinces. Total assets grew after a year and products being offered increased significantly. The company's good market standing enabled it to grow even more.

At present, Sigjohn has a total of 112 products (generic and branded) for cough and cold remedies, analgesic and antipyretic, non-steroidal/anti-infalmmatory, anti-bacterial, anti-asthmatic, antacid, anti-spasmodic, anti-tuberculous agents, antihistamine, anti-protozoal, anthelmintic, antimalarials, vitamins and multivitamins, anti-anemic, adrenal corticosteroid, antihypertensive, anti-diarrheal, diecretic and nutritional supplements available in the market. Ten of which are being advertised at PIMS for reference of hospitals and doctors.

According to Henry Ford, Board Chairman of Ford Motor Corporation, "...businesses learned that however legal and proper its actions, to act in terms of profits or loss alone is not quite good enough. Something more is required - a positive awareness of national goals and objectives, social, as well as economic...".

And to fulfill its commitment and worth role in social awareness, Sigjohn Pharma., in cooperation with San Marino Laboratories, has formed a team of doctors, nurses and nuns for medical missions at least every quarter of the year to various depressed barrios and areas all over the Philippines.

The company's labor force increased with the company hiring additional sales representatives nationwide. Total assets grew even better. But the vision of the company does not stops there. Additional innovative products and plans for adding another line of business like importaion of various pharmaceutical products are also being considered to be carried out in the near future. This only shows the company's endless pursuit for total satisfaction and service to its clients in an industry where technology and change are valued and inevitable.