Product Category


ICH-Q7 GMP Manufactured Product

HEPES, Free Acid, Ultra-Low UV, LBLE
GMP Excipient Grade

Low Bioburden, Low Endotoxin, GMP Manufactured

Product Code: HEPE-3252

Intended For Use As An Excipient

HEPES is a zwitterionic buffer used to maintain pH of media used in cell cultures. It is one of Good’s twelve buffers that has a pKa value similar to its pH value making it an ideal buffer for pH maintenance. It has only one restriction, it interferes with the Folin protein assay. This buffer can form radicals so it is not suitable for redox studies. HEPES is used as a Good’s buffer because it has low UV absorptivity, minimal reactivity, stable pH and is soluble in water.


Product Specifications

Absorbance (1M)

250 nm

260 nm

280 nm

0.0500 a.u.
0.0400 a.u.
0.0400 a.u.
Absorbance (0.05M)

250 nm

260 nm

280 nm

 0.0500 a.u.
0.0500 a.u.
0.0500 a.u.
Appearance and Color  
White / Crystals
Assay, Dried Basis  
99.5% min.
0.005% max.
≤ 5 EU/g




 None Detected

None Detected

None Detected

Heavy Metals (as Lead)  
1 ppm max.
Identification (IR)  
Passes Test
Insoluble Matter  
≤ 0.01% max.

Microbial Content


≤ 50 CFU/g
≤ 50 CFU/g

pH (1% Soln.)

4.7 – 5.6


7.45 – 7.65
Residue on Ignition  
0.1% max.
Solubility (1% soln.)  
Pass / Clear Solution
Solubility (0.05M) Passes Test
0.005% max.
Trace Metals

Arsenic (As)

Copper (Cu)

Iron (Fe)

Lead (Pb)

5 ppm max.

5 ppm max.

5 ppm max.

5 ppm max.

Water Content (Karl Fischer) 0.5% max.
Printable Version
Key Compliance Attributes of BioSpectra Grades Bio Excipient Grade ICH-Q7 Compliant Manufactured
Suitable for Research and Diagnostic  
Each Batch 100% Analyzed  
Management of Change  
Validated Analytical Methods  
Compendial Testing  
Trace Metals Analyzed  
Stability Testing Program  
BioSpectra Supply Chain Audit Trail  
Product Origin Statement  
Customer Quality Audits  
Validated Manufacturing Process  
US Manufactured at BioSpectra  
Customized Additional Specifications  
Multi-Compendial Testing  
Low Bioburden Low Endotoxin (LBLE)  
Enzyme Tested  
Suitable for use as Excipient  
Microbial / Endotoxin Tested  
Manufactured in FDA Registered Facility  
Customized Manufacturing Schedule  
Custom Regulatory Packet  
Accelerated Stability  
Video Conference access to BioSpectra Sites  
Complete access to Product Traceability  
Access to Supply Chain Information  
ICH-Q7 Qualified Utilities  
ICH-Q7 Compliant Manufactured  
Type II Drug Master File  

Yes-imageindicates an attribute or level of compliance which is granted or available based on the purchase of the product grade.
Bio Excipient Grade: Intended for use as ICH-Q7 Compliant Active Pharmaceutical Ingredient 
LBLE: LBLE applies when product specifications include requirements for Bioburden Testing (TAMC/TYMC and/or Endotoxin).
LBLE stands for Low Bioburden, Low Endotoxin non-sterile products suitable for further use in parenteral manufacturing and other sterile applications.


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CAS #: 7365-45-9

Formula: C8H18N2O4S

Sol. In H2O (g/L): 400

F.W.: 238.30 g/mol

pH @ 20°C: 5.0 - 6.5

Useful pH: 6.8 - 8.2

pKa @ 20˚C: 7.55

General Product Description:

  • The manufacturing of HEPES, HEPE-3252 is performed at BioSpectra’s Bangor and Stroudsburg, PA facilities utilizing multi-use equipment. Equipment used in the manufacturing of HEPE-3252 is cleaned in accordance with BioSpectra’s Process Cleaning Validation Master Plan.
  • HEPES is a White Crystalline Product.
  • Molecular Formula: C8H18N2O4S
  • Molecular Weight: 238.30 g/mol.
  • CAS Number: 7365-45-9.
  • There are no known major food allergens (as defined by FDA and WHO) in the manufacture of this product.
  • BioSpectra certifies that all HEPES HEPE-3252 manufactured at BioSpectra and its raw materials are not derived from or come in contact with animal parts, products, and/or byproducts.
  • HEPES manufactured at BioSpectra and any raw materials used in the manufacture of HEPES at BioSpectra are not subject to genetic modification.
  • Synonyms: N-(2-Hydroxyethyl)piperazine-N’-2- ethanesulfonic acid, 2-[4-(2-hydroxyethyl)piperazin-1-yl] ethanesulfonic acid.


ELEMENTAL IMPURITIES: This product complies with ICHQ3D, USP <232> and USP <233> requirements for Elemental Impurities.

RESIDUAL SOLVENTS: Based on the manufacturing process and the controlled handling, storage and analysis of this product, this product complies with the requirements and specifications listed in the current USP method <467> Tables 1, 2, 3, or 4.

GMP Compliance:

Bio Excipient Grade HEPES, HEPE-3252 is suitable for use as an excipient. It is manufactured in accordance with the ICH-Q7 Good Manufacturing Practice Guide. This grade of HEPES is not suitable to be used as an Active Pharmaceutical Ingredient, Drug Product or Household Item.

Retest Date:

The recommended retest period for HEPES is two years from the date of manufacture.

Storage and Shipping Conditions:

Ship and store in ambient temperature. Store in a clean and dry area. Store in the original container.

Package Sizes:

10kg, 25kg and 50kg pails.

Additional Packaging Information