Raman Spectroscopy: What is it?

PharmID Verify uses Raman Spectroscopy to identify medication and concentration in sterile compounded IV products. The Raman effect was discovered in 1923. Like gravitational waves predicted by Einstein, it took many decades for the technology to be developed to actually see it. Over the last 30 years, Raman Spectroscopy has migrated from the lab to industrial uses. Today PharmID brings this cutting-edge technology to your IV Room.

How does Raman Spectroscopy work?

Raman Spectroscopy uses a millisecond focused laser pulse to excite the chemical bonds in a medication in sterile solution. Powerful spectrometers then capture the spectral fingerprint of the medication and filter out the incident laser light. The fingerprint is unique to the medication.


How does it identify the medication?

The spectral fingerprint is mapped against a reference database of spectral standards that we are constantly updating and adding to.

When a pattern matches in terms of peaks and valleys, the relationships between them and the frequencies, then we can say that the medications are the same. An example of a spectral fingerprint looks like this.


How do you measure concentration?

The correlation between the intensity of the Raman spectral pattern and the concentration is 1:1 and linear. For example, if a spectral pattern is twice the height of another sample, it has exactly twice the concentration. The measured concentration is mapped against this linear model mathematically to determine whether the expected concentration in the compounded sterile product matches the predicted model based on measured spectral intensity.


How accurate is it?

Like a true fingerprint, PharmID Verify identifies a drug entity 100% of the time; it either matches the reference sample or it does not.

The identification of concentration is less than 1% variance of expected concentration. PharmID Verify allows an administrator to set the variance window for concentration. Because standards in pharmacy allow for 5% +/- in compounding and PharmID Verify is more accurate than this, we allow the site to manage the variance limits.

Does using PharmID Verify change or interact with the medication at all?

This is one of the advantages of PharmID Verify is that the light energy used does not cause any changes to the medication or the container. In fact, PharmID Verify scans through the medication container (currently IV Bags and plastic syringes) to sample the medication and does not require removal of a sample that could negatively impact final dose and sterility. The laser scan only lasts milliseconds and covers a space of less than 1mm^3 in the sample. Raman is used widely in pharmaceutical manufacturing with no adverse effect on active pharmaceutical ingredients.