Related Experiment Video
Updated: Jun 27, 2026
Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
Published on: October 12, 2012
In vitro stability of enoxaparin solutions (20 mg/mL) diluted in 4% glucose
Rahul P Patel1, Christian Narkowicz, Glenn A Jacobson
1School of Pharmacy, University of Tasmania, Hobart, Tasmania, Australia. rppatel@utas.edu.au
Insights
Diluting enoxaparin (antithrombotic) with 4% glucose and storing it at 4°C preserves over 99% of its activity for 31 days. This offers a stable method for preparing pediatric enoxaparin doses.
Area of Science:
- Pharmacology
- Pediatric Medicine
- Drug Stability
Background:
- Enoxaparin is a critical antithrombotic for pediatric prophylaxis.
- No commercial pediatric dosage form exists, necessitating daily extemporaneous preparation.
- The stability of diluted enoxaparin for pediatric use is not well-established.
Purpose of the Study:
- To evaluate the stability of enoxaparin diluted to pediatric concentrations.
- To assess the impact of different diluents (sterile water, 4% glucose) and storage conditions on enoxaparin stability over 31 days.
Main Methods:
- Enoxaparin (100 mg/mL) was diluted to 20 mg/mL with sterile water or 4% glucose.
- Solutions and undiluted control were stored at 4°C, -12°C, or -80°C.
- Antifactor Xa (AFXa) activity was measured on days 0, 7, 14, and 31 using chromogenic assay.
Main Results:
- Enoxaparin diluted with 4% glucose lost minimal AFXa activity (0.6%–9.6%) across storage temperatures.
- Enoxaparin diluted with sterile water showed greater activity loss (10.0%–18.2%) at all temperatures.
- Undiluted enoxaparin lost significant activity at -12°C and -80°C but remained stable at 4°C.
Conclusions:
- Dilution with 4% glucose and storage at 4°C maintains >99% of enoxaparin's initial AFXa activity for 31 days.
- This method provides a stable alternative to daily preparation of pediatric enoxaparin doses.
- 4% glucose is a promising diluent for stable extemporaneous pediatric enoxaparin formulations.
Background:
Enoxaparin is an antithrombotic used for the prophylaxis of pediatric patients. Treatment can extend over weeks or months but there is no commercial pediatric dosage form of enoxaparin available. The stability of extemporaneously diluted enoxaparin, at pediatric dosage levels, has not been thoroughly evaluated. Therefore, pediatric doses are prepared extemporaneously on a daily basis, which results in subsequent limitations and problems.
Objective:
The aim of this study was to determine the stability of enoxaparin diluted with sterile water or 4% glucose solution over a 31-day period under different storage conditions.
Methods:
Enoxaparin (100 mg/mL) diluted with sterile water or extemporaneously prepared sterile 4% glucose to 20 mg/mL and undiluted enoxaparin (control) were kept at 4 degrees C, -12 degrees C, or -80 degrees C. The antifactor Xa (AFXa) activity of stored solutions was determined by chromogenic assay on days 0, 7, 14, and 31 and was compared with the control solution.
Results:
Enoxaparin solution (20 mg/mL) diluted with 4% glucose lost 0.6%, 2.2%, and 9.6% of its initial AFXa activity after 31 days at 4 degrees C, -12 degrees C, and -80 degrees C, respectively. Enoxaparin solution (20 mg/mL) diluted with water lost 10.0%, 12.4%, and 18.2% of its original AFXa activity at 4 degrees C, -12 degrees C, and -80 degrees C after 31 days, respectively. Undiluted enoxaparin solution (100 mg/mL) lost 15.8% and 20.2% of its initial activity after 31 days at -12 degrees C and -80 degrees C, respectively, but no loss was detected at 4 degrees C.
Conclusions:
Dilution of enoxaparin (100 mg/mL) with 4% glucose to 20 mg/mL and storage at 4 degrees C preserved >99% of the initial AFXa activity after 31 days, compared with a loss of 10% of the initial activity in the enoxaparin solution diluted with water (to 20 mg/mL) and stored under the same conditions. Dilution with 4% glucose offers a potential method for the preparation of stable pediatric doses of enoxaparin.
