Infusion buffer capacity

Furosemide injection may be administered by slow IV injection or by intermittent or continuous IV infusion at a rate not exceeding 4 mL/min. Therefore, the question arises whether photoprotection of the drug reservoir is necessary during parenteral administration. Furosemide injection contains the sodium salt of furosemide formed in situ by the addition of sodium hydroxide during the manufacturing process. The injection solution has a pH of 8 to 9.3. In use, it can be mixed with weakly alkaline and neutral infusion solutions (e.g., 0.9% sodium chloride or Ringer s solution) or with some weakly acidic solutions having a low buffer capacity (e.g., dextrose 5% in water). 

Furthermore, the author believes that buffer capacity curves, which may be established from neutralization curves, are of value in estimating the composition of liquids containing a mixture of various acids and bases. Examples of such liquids are soil infusions, beer, milk, fruit juices, foodstuffs, etc. A detailed discussion of the subject is beyond the scope of this monograph. ... 

Concentrates or powders for injections or infusions may be diluted, dissolved, or suspended ex tempore in several different media prior to administration. The most common solutions for this purpose are listed in Table 14.3. These are sterile, isotonic, aqueous solutions, but differ with respect to pH, ionic strength, buffer capacity, and chemical composition. As described in Section 14.2, these physicochemical properties may be highly important for the photochemical stability of a dissolved compound choice of medium can be critical and photochemical behavior can change dramatically in different media. 

Large volume infusions should have a physiological pH, e.g. pH 7.4 and little or no buffer capacity. In general infusimis with pH 5-9 are tolerated by peripheral veins. 

---