Dow Water & Process Solutions

Industries & Applications

Active Pharmaceutical Ingredients (API’s)

Two of Dow Water & Process Solutions ion exchange resins (IX) — DUOLITE™ AP143 and AMBERLITE™ IRP69 — are used as active pharmaceutical ingredients (API) and available by prescription to treat Hypercholesterolemia and Hyperkalemia. They are compendial drugs listed in the U.S., British and European Pharmacopoeia under the names Cholestyramine Resin and Sodium Polystyrene Sulfonate, respectively. Administered as suspensions, these APIs are non-systemic, passing through the GI tract and not entering the bloodstream.

These products are manufactured at Dow’s facilities in Chauny, France and are fully supported by Drug Master File (DMF) files. The Chauny facility meets current Good Manufacturing Practice (cGMP) standards. Please contact us for more information about Regulatory Compliance and Support.


Elevated levels of cholesterol can increase the likelihood of cardiac arrest. CHOLESTRYAMINE RESIN (DUOLITE AP143) works by non-systemically removing bile acids from the GI tract. Because cholesterol is a key intermediate in the biosynthesis of bile acids present in the GI tract, when bile acids are bound to an anion exchange resin and removed from the body, the increased metabolism of cholesterol to replenish these bile acids results in lower serum cholesterol levels. The typical dosage of cholestyramine resin (DUOLITE AP 143) is between 8 and 24 grams per day for extended periods. While a number of different formulations are available for commercial use, the predominant one is a powder sachet.


Excess potassium in the blood, a potentially life-threatening condition, is common in patients with chronic renal failure. The most effective acute treatment is a simple ion exchange (IX) with SODIUM POLYSTYRENE SULFONATE (AMBERLITE IRP69) The sodium ions present in the resin are exchanged with the excess potassium in the blood stream as the resin passes through the GI tract. The typical dosage of sodium polystyrene sulfonate (AMBERLITE IRP69) is between 15 and 60 grams per day as long as the condition persists. Formulations are typically administered as aqueous suspensions.

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