To prepare a 0.9% saline solution in a 12 oz bottle, it’s essential to calculate the precise amount of salt required. This concentration is crucial in medical settings where isotonicity with bodily fluids is necessary for various treatments.

Understanding the Solution Concentration:

A 0.9% saline solution denotes that there are 0.9 grams of salt dissolved in 100 mL (which equals 100 grams) of water.

Calculating for 12 oz (354.88 mL) of Water:

1. Convert ounces to milliliters: 12 oz is approximately 354.88 mL.
2. Calculate 0.9% of 354.88 mL: Amount of salt (grams)=0.9100×354.88\text{Amount of salt (grams)} = \frac{0.9}{100} \times 354.88Amount of salt (grams)=1000.9​×354.88 Amount of salt (grams)=0.009×354.88\text{Amount of salt (grams)} = 0.009 \times 354.88Amount of salt (grams)=0.009×354.88 Amount of salt (grams)=3.19392\text{Amount of salt (grams)} = 3.19392Amount of salt (grams)=3.19392
3. Rounding Off:
   • Round the calculated amount to an appropriate precision, typically to the nearest tenth of a gram.

Therefore, approximately 3.2 grams of salt should be added to a 12 oz bottle to achieve a 0.9% saline solution. This solution matches the salinity of bodily fluids, making it suitable for medical purposes such as intravenous infusions and wound irrigation. Ensuring isotonicity is crucial in maintaining cellular integrity and minimizing discomfort during medical procedures.

Creating such solutions accurately is vital in healthcare to meet specific physiological needs and ensure patient safety and comfort. Always use calibrated measuring tools to achieve precise concentrations, adhering to established medical guidelines for saline solution preparation and administration.