Our Story

Over a Century in the Making

From corner drug store to industry cornerstone.


The Forerunners

Diamond Drugs, Inc.'s history began in 1910 when pharmacist Clark Neal opened a drug store in downtown Indiana, PA. Neal operated for one year before selling to Noble Miller in 1911, who operated it for 25 years before selling to the Diamond Drug Corporation of Johnstown, PA in 1937.

The Zilners Set Up Shop

Pharmacists Gilbert and Joan Zilner purchased Diamond Drugs on Philadelphia Street in Indiana, PA from the Diamond Drug Corporation. Aside from serving retail customers, they expanded the business by filling prescriptions for local long-term care facilities.

Going Beyond the Counter

After a decade of expanding local retail and LTC business, Diamond was awarded a bid to service a nearby state correctional facility in Greensburg, PA. It's the beginning of the company's correctional division.

Becoming a Family Business

Mark Zilner, son of Gilbert and Joan, earns his pharmacy degree from Northeastern University in Boston and joins the family business. He also brings a new set of ideas to transform Diamond.

Building for Growth

Due to the growth of correctional and LTC clients, Diamond breaks ground on a new corporate headquarters and production facility on Kolter Drive in Indiana, PA.

Moving to the Top

Diamond becomes the nation's largest correctional pharmacy provider after winning a large correctional contract to serve over 50,000 additional patients.

Expansion Everywhere

Diamond’s corporate facility undergoes another renovation to add more automation and pharmacy space, expanding the facility to 135,000 square feet. By 2003, Diamond has over 500 employees and serves 38 states.
2006 - 17

Acceleration and Innovation

Diamond completes construction of a new closed-door Medical Supply facility and establishes subsidiary companies devoted to drug repackaging, electronic health records, and mail order pharmacy, all located in Indiana. Diamond also opens satellite pharmacies in Leesport, PA and Westerville, OH.
2020 - Present

A Diamond Dynasty

Diamond continues to be family-owned and is one of Indiana County's largest employers, with nearly 1,000 employees. Mark Zilner, RPh leads Diamond into its fifth decade under the Zilner family as president and CEO.

Contact Us

Our history is also defined by commitment to our customers. We'd love the opportunity to serve you.