Erythromycin lactobionate is available as a lyophilized powder in single-dose vials containing the equivalent of 500 mg of erythromycin activity.1150 The lactobionic acid content in each vial is 244 mg.1150 Reconstitute vials with 10 mL of sterile water for injection to yield a solution containing 50 mg/mL of erythromycin activity.1150 The manufacturer states only sterile water for injection should be used to reconstitute the vials; other diluents may cause precipitation during reconstitution.1150 Do not reconstitute vials with diluents containing preservatives or inorganic salts.1150 The reconstituted solution must be further diluted in a sodium chloride 0.9%; Ringer's injection, lactated; or Normosol R to a concentration of 1 to 5 mg/mL of erythromycin activity prior to administration; the manufacturer states other infusion solutions should not be used.1150
Erythromycin lactobionate also is available in ADD-Vantage vials containing the equivalent of 500 mg of erythromycin as a lyophilized powder.1151 ADD-Vantage vials should be prepared with 100 mL of dextrose 5% or sodium chloride 0.9% in ADD-Vantage diluent bags to provide a solution containing 500 mg of erythromycin activity in 100 mL (approximately 5 mg/mL of erythromycin activity).1151
pH
Reconstitution with sterile water for injection to a 50-mg/mL concentration results in a solution with a pH of 6.5 to 7.5.20; 1150
Osmolality
Erythromycin lactobionate 50 mg/mL in sterile water for injection has an osmolality of 223 mOsm/kg.50
The osmolality of erythromycin lactobionate was calculated for the following dilutions:1054
| Osmolality (mOsm/kg) | ||
|---|---|---|
| Erythromycin in Diluent | 50 mL | 100 mL |
| 500 mg in Dextrose 5% | 273 | 265 |
| 500 mg in Sodium chloride 0.9% | 299 | 291 |
| 1 g in Dextrose 5% | 287 | 273 |
| 1 g in Sodium chloride 0.9% | 313 | 300 |
Trade Name(s)
Erythrocin Lactobionate-I.V.
Erythromycin lactobionate may be administered by continuous or intermittent intravenous infusion; it must not be given by direct intravenous injection.1150 To minimize venous irritation, slow continuous infusion of a 1-mg/mL concentration is preferred.1150 Erythromycin lactobionate prepared from ADD-Vantage vials are intended for intermittent intravenous infusion only.1151 By intermittent infusion, one-fourth of the daily dose at a concentration of 1 to 5 mg/mL in at least 100 mL of infusion solution may be given over 20 to 60 minutes every 6 hours.1150; 1151
Intact vials and ADD-Vantage vials should be stored at controlled room temperature.1150; 1151 Solutions reconstituted with sterile water for injection are stable for 2 weeks stored under refrigeration or 24 hours at room temperature.1150 Final diluted solutions should be completely administered within 8 hours.1150
Solutions prepared from ADD-Vantage vials should be completely administered within 8 hours if prepared in sodium chloride 0.9% or 2 hours if prepared in dextrose 5%.1151
pH Effects
The stability of erythromycin lactobionate is extremely pH dependent. It is most stable at pH 6 to 820; 1935 or 9.1101; 2596 Erythromycin lactobionate is unstable in acidic solutions.1150 Decomposition occurs at an increasingly more rapid rate as the pH approaches 4.20 A pH over 5.5 is recommended for the final diluted solution. At pH 5.5 or below and at pH 10 or above, erythromycin lactobionate is particularly unstable, with 10% decomposition occurring in about eight or nine hours. The following pH profile was determined for erythromycin in solution:1101
| Solution pH | Approximate Time for 10% Decomposition (t90) |
|---|---|
| 5 | 2.5 hr |
| 5.5 | 8.8 hr |
| 6 | 1 day |
| 7 | 4.6 days |
| 8 | 7.3 days |
| 9 | 2.6 days |
| 10 | 8.8 hr |
| 11 | 53 min |
Erythromycin lactobionate can alter the pH of solutions and give itself some protection against decomposition for varying periods. The length of time is dependent on the initial pH and the buffer capacity of the solution.48 The pH of unbuffered dextrose 5% is raised 1 pH unit by the addition of erythromycin lactobionate.20 The use of admixtures with a pH of less than 5 is not recommended. If the admixture pH is 5 to 6, it should be used immediately.48
The effect of buffering erythromycin lactobionate (Abbott) solutions was evaluated. Erythromycin lactobionate 2 mg/mL in sodium chloride 0.9% (pH 7.15 to 7.25) exhibited 5% losses in about 20 days at 5°C. However, buffering with sodium bicarbonate to pH 7.5 to 8 extended stability, with 5% losses occurring in about 85 days at 5°C.1587
Freezing Solutions
Erythromycin lactobionate (Abbott) 500 mg/110 mL in sodium chloride 0.9% in PVC bags was frozen at -20°C; no loss occurred after 12 months of storage followed by microwave thawing. Furthermore, the solution was physically compatible, with no increase in subvisible particles. In addition, no erythromycin loss was found after 6 months at -20°C followed by 3 freeze-thaw cycles.1612
For a list of references cited in the text of this monograph, search the monograph titled References.