Calcium polystyrene sulfonate

Calcium polystyrene sulfonate (CAS 37286-92-3), commonly abbreviated as CPS, is a cation-exchange resin used in pharmaceutical manufacturing and clinical formulation.

Where is Calcium polystyrene sulfonate used?

• Pharmaceutical manufacturing: bulk API for branded and generic drug products
• Clinical formulation: active basis for oral and rectal hyperkalemia treatments
• It is formulated into oral suspensions, powders for reconstitution, and rectal enema preparations for hospital and outpatient use.
• Specialty compounding pharmacies prepare patient-specific dosage forms where commercial products are unavailable or unsuitable.

Good to know: It functions by exchanging calcium ions for potassium ions in the gastrointestinal tract. CPS is the active pharmaceutical ingredient in finished-dose products designed to reduce elevated potassium levels in patients with renal impairment.

Commercial specifications

• Defined exchange capacity, particle size distribution, and moisture content
• Certificates of analysis and pharmacopoeial alignment with USP, BP, or EP guidelines