Sodium Chloride Injection: The Benefits And Drawbacks Of Using It Over BNS

August 24, 2022

Sodium chloride is also called saline. Health care professionals (HCPs) often refer to it as ‘normal saline.’ It is administered intravenously for electrolyte replenishment. Sodium Chloride injection contains 0.9% NaCl in sterile water without any bacteriostatic agent.

9 mg sodium chloride per ml of water is the same constituency equivalent to the osmolarity of blood plasma. Thus it does not harm the blood cells due to hyperosmolarity or hypo-osmolarity.

HCPs also refer to normal saline with other names like, i.e., physiologic saline, non-pyrogenic saline, 0.9% NaCl, etc.

Sodium Chloride injection

Sodium chloride injection is a sterile isotonic solution of sodium chloride in water for injection. It does not contain antimicrobial agents but has approximately 154mEq of sodium and chloride ions per liter.

It can be used as a sterile carrier in drug solutions or suspensions for parenteral administration. It is also employed in the reconstitution of medications for injection.

To maintain patency, sodium chloride injection is frequently used as a catheter or IV line flush. Catheters and IV lines are constantly used to administer fluids and medications and draw blood for laboratory analysis.

2mL is typically used for flushing the line after each use or every 8 hours if the line is not used.

What is Bacteriostatic Normal Saline (BNS)?

Bacteriostatic normal saline is used for the same purposes, but it has a bacteriostatic agent, which is mandatory for the manufacturer to specify on the label. The bacteriostatic agent, like 0.9% Benzyl alcohol, acts as a preservative in the multidose vial. It is used for dilution and IV flushing.

Comparison between Normal Saline and BNS

Normal saline and BNS are commonly used for dilution and IV flushing. Both have the same uses on the surface, but their properties vary due to the bacteriostatic agent.

Benefits of sodium chloride over bacteriostatic sodium chloride

The bacteriostatic agent in the BNS is the only difference in constituents of the two. This is where the properties of both the diluents differ.

1- Interaction with the bacteriostatic agent

A bacteriostatic agent used in the BNS may have a drug interaction with the medication or drug substance. Bacteriostatic agents can also interact with the patient or the disease. Therefore the choice of diluent varies from drug to drug and patient to patient.

2- Irritation on the injection site

A bacteriostatic agent like Benzyl Alcohol is reported to cause inflammation at the injection site, which is not the case with Sodium Chloride injection without a bacteriostatic agent.

Drug interactions with sodium chloride

Sodium chloride without a bacteriostatic agent can also cause drug interactions, i.e., patients taking corticosteroids or corticotropin should exercise caution.

It should also be avoided in patients with a dilution of serum electrolytes, pulmonary edema, congested states, or overhydration after the administration.

3- Multidose vials

The most common use of normal bacteriostatic saline is the multidose vials, where 0.9% benzyl alcohol acts as a preservative for use over time. However, care must be taken to avoid contamination.

On the other hand, sodium chloride injection without a bacteriostatic agent is supplied in a single-dose plastic container. The fill volume for sodium chloride injection is 250/250, 500/500, or 1000/1000.

Properties of sodium chloride injection

Following are the specific properties of Sodium Chloride injection:

  • 0.9% sodium chloride in sterile water. It is a sterile and non-pyrogenic formulation.
  • Intended for administration through IV route only.
  • The pH of the solution is 5.6
  • It has no antimicrobial agent and is therefore intended for a single dose only. If there is any leftover amount of Sodium chloride, it should be discarded.
  • The plastic container is created with multilayer polyolefin, and the formulation is stored at 25 °C.

Management and monitoring

After the administration of NaCl, lab reports should be checked explicitly for any electrolyte imbalance, volume status, and acid-base disturbances. Patients must be examined for signs and symptoms of fluid overload and dehydration.

Even though normal saline is used widely, an interprofessional approach among physicians, pharmacists, and nurses is always needed for its proper administration.

The benefits and drawbacks of using Normal saline injection without a bacteriostatic agent are evident in the above-mentioned pharmaceutical properties of both products.

Picture of by Kinza Khan
by Kinza Khan

August 24, 2022