Sevelamer Hydrochloride API is a non-absorbed, cross-linked polymeric phosphate binder used in pharmaceutical formulations for the management of hyperphosphatemia associated with chronic kidney disease. It is chemically described as poly(allylamine-co-N,N′-diallyl-1,3-diamino-2-hydroxypropane) hydrochloride. The polymer contains multiple protonated amine groups that interact with dietary phosphate through ionic and hydrogen bonding.
Sevelamer Hydrochloride is hydrophilic but insoluble in water and is not systemically absorbed following oral administration. Its non-absorbed polymeric nature distinguishes it from conventional low-molecular-weight pharmaceutical ingredients.
Sevelamer Hydrochloride is a cross-linked polymer obtained from poly(allylamine hydrochloride) through crosslinking with epichlorohydrin. Because it is a polymeric substance, its composition is represented using variable polymerization parameters rather than a single conventional molecular formula or fixed molecular weight. DailyMed represents the structure using polymer variables and identifies approximately 40% of the amines as protonated.
The FDA GSRS-associated identity for Sevelamer Hydrochloride is UNII GLS2PGI8QG, with CAS Registry Number 152751-57-0 for the hydrochloride polymer substance. A separate CAS number, 52757-95-6, is widely used for the broader Sevelamer substance.
Sevelamer Hydrochloride is used as a phosphate-binding active pharmaceutical ingredient. In the gastrointestinal tract, protonated amine groups on the polymer bind phosphate from food and reduce its absorption, thereby lowering serum phosphorus concentrations.
The API is associated particularly with pharmaceutical formulations intended for patients with chronic kidney disease requiring control of elevated serum phosphorus. Sevelamer Hydrochloride was the active ingredient of the original Renagel formulation.
For Sevelamer Hydrochloride, phosphate-binding capacity is an important functional quality attribute. Unlike a conventional small-molecule API, simply measuring an HPLC assay does not adequately describe the functional performance of the polymer.
Published analytical work describes an ion-chromatographic phosphate-binding assay in which the amount of phosphate bound by the polymer is calculated from the difference between initial and unbound phosphate concentration.
Process-development literature reports Sevelamer Hydrochloride phosphate-binding capacities in the approximate range of 4.7–6.4 mmol/g, with a preferred range of approximately 5.3–6.0 mmol/g for the particular process described. These values are process-specific and should not be presented as a universal pharmacopoeial release limit.
Quality control of Sevelamer Hydrochloride requires polymer-specific analytical procedures. Important quality attributes can include:
USP has recognized Sevelamer Hydrochloride as a USP Reference Standard, confirming its use in pharmaceutical analytical testing.
Current USP publications also demonstrate that sevelamer products require specialized tests such as Limit of Allylamine and Phosphate Binding Capacity, rather than relying solely on conventional small-molecule HPLC assay methodology.
Swapnroop Drugs and Pharmaceuticals provides pharmaceutical API manufacturing and quality-focused capabilities for active pharmaceutical ingredients and specialized pharmaceutical materials.
Sevelamer Hydrochloride can be manufactured and evaluated according to applicable product specifications, customer requirements and validated analytical procedures. Particular attention can be given to polymer identity, moisture, residual process impurities and functional phosphate-binding performance.
Sevelamer Hydrochloride should be protected from excessive moisture and stored in tight containers under controlled environmental conditions. Historical USP material specifies storage in tight containers at controlled room temperature.
Because the material is a hydrophilic polymer, appropriate moisture-protective packaging is important to maintain consistent physical and functional properties.
Documentation available according to applicable product and regulatory requirements may include:
Sevelamer Hydrochloride requires polymer-specific characterization and functional testing rather than conventional small-molecule API testing alone. Swapnroop focuses on controlled pharmaceutical manufacturing, analytical quality evaluation and documentation support for API requirements.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 5.0% |
| Water Content | NMT 5.0% |