Purified water is regarded as the lifeblood of every pharmaceutical facility. Purified water is required for all important manufacturing processes, including the production of tablets, syrups, ointment, and parental products. To maintain specific parameters such as conductivity, TOC, pH, total, microbial counts, sulphate, nitrate, chloride, and so on, water must go through several filtering procedures such as softening, reverse osmosis, ultra filtration, ion exchange, and chemical dosing etc.

Our post is about one of the water pollutants known as “TOTAL ORGANIC CARBON.” How pharmaceutical companies handle organic risks. Total Organic Carbon (TOC) analysis has become the standard quality test for purified water and water for injection by organizations such as the United States Pharmacopoeia (USP), Japanese Pharmacopoeia, and the European Pharmacopoeia. The USP has gone so far as to demand TOC water monitoring at all stages of the pharmaceutical sector. TOC should be NMT 500 ppb according to pharma water standards.

What is TOC??

The total organic carbon (TOC) in pure water and aqueous systems is a measure of the total amount of carbon in organic substances. TOC is a valued, analytical technique that is applied by organizations and labs to determine how suitable a solution is for their processes. Water will inherently include some organic molecules unless it is ultrapure, thus knowing how much is important.

The analysis of TOC measures following parameters;

  • Total carbon (TC),
  • Inorganic carbon (IC),
  • Total organic carbon (TOC),
  • Purgeable organic carbon (POC) and
  • Non purgeable organic carbon (NPOC).

Principle of measuring TOC:-

Photo catalytic oxidation, chemical oxidation and high temperature combustion are three methods available to measure TOC.

Photo catalytic oxidation is the commonly used methods in pharmaceuticals industry.  

The testing water enters the analyzer and travels through a pressure regulator, which regulates sample pressure before it reaches downstream components. The water is separated into two portions here, with a portion of the flow going to a by-pass stream line where the resistivity/conductivity and temperature are monitored using a resistivity sensor. The other part goes via a sensor to evaluate the conductivity before oxidation.

After passing through the conductivity test, the water enters the oxidation phase, where it is exposed to high-intensity UV light at around 185 nm, efficiently oxidizing the water to CO2. Water goes via another sensor after oxidation to evaluate conductivity. The discrepancies between the values collected by both conductivity sensors are calculated, and the concentration of organic contaminant in the entering water stream is directly related. The water from the sensor is then routed through a flow meter with a fine flow adjustment before exiting through an outlet that may either be rejected or recycled.

How to control Total Organic carbon in water:-

  1. Heating: – TOC is reduced by heating. If the component contributing to TOC is volatile (Chloroform), increasing the temperature causes it to partition from the aqueous phase to the vapor phase. However, this procedure is only applicable in the laboratories.
  2. UV Treatment: – Like a basic oxidation process, UV dissociates water molecules by producing free OH- radicals. When OH- reacts with TOC hydrocarbons, water and CO2 molecules are formed. The TOC in the water was lowered as a result of this.
  3. Other methods like Activated carbon filter, RO membrane , softener and de-ionized process

We hope that this blog will assist you in better understanding TOC. Please contact us at sales@hvax.in/arvind.s@hvax.in for additional information about pharmaceutical clean utilities.

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