How Efficient Is Your Process? Here's How to Find Out

Green Chemistry Institute logo

The ACS commitment to sustainability permeates the entire society, but the leader in that commitment is ACS GCI. Ten years ago, the Green Chemistry Institute joined forces with ACS “in an increased effort to address global issues at the intersection of chemistry and the environment”. The institute is committed to enabling and catalyzing “the implementation of green chemistry and engineering principles into all aspects of the global chemical enterprise”. The commitment to green chemistry in industrial innovation includes three groups: the pharmaceutical, formation, and chemical manufacturers’ roundtables.

This article features one accomplishment of the Pharmaceutical Roundtable (ACS GCIPR). The mission of ACS GCIPR is “to catalyze the implementation of green chemistry and green engineering in the global pharmaceutical industry”. One of its goals is to create tools for innovation.

In February 2011, the Pharmaceutical Roundtable published a process mass intensity tool (PMI) for measuring process efficiency.

Process mass intensity = quantity of raw materials input (kg) / quantity of bulk API out (kg)


  • Process is all steps of a synthetic path from commonly available materials to the final bulk active pharmaceutical ingredient (“API”).
  • Raw materials input is all materials, including water, that are used directly in the process of synthesizing, isolating, and purifying the API final form.
  • Bulk API out is the final form of the active ingredient that was produced in the synthesis, dried to the expected specification.

The roundtable members created the PMI metric to encourage sustainability in the pharmaceutical industry. Using the metric, companies can track their environmental footprint and measure their process efficiencies. The PMI also allows companies to share and compare their data in an effort to enhance sustainability throughout the pharmaceutical industry.

Not only did the group create the metric for measuring process mass intensity, but they developed a calculator that can be found at the ACS GCI website. It is a spreadsheet with embedded calculations that determine overall PMI and the PMI for solvents, water, and reagents.

The next step will be to involve suppliers and measure the PMI from raw materials through the final product.

See also “Engineering Research Areas for Sustainable Pharmaceutical Manufacturing” in this series.