Aminophylline is available as a 25-mg/mL solution in 10- and 20-mL single-dose vials.1563 Aminophylline is a 2:1 complex of theophylline and ethylenediamine in water for injection.1563 The solution may contain an excess of ethylenediamine for pH adjustment.1563 Aminophylline dihydrate is approximately 79% of anhydrous theophylline by weight; each mL contains aminophylline dihydrate 25 mg equivalent to 19.7 mg of anhydrous theophylline.1563
pH
From 8.6 to 9.1563
Osmolarity
The calculated osmolarity of the injection is 170 mOsm/L.1563
Osmolality
The osmolality was determined to be 114 mOsm/kg by freezing-point depression.1071
The osmolality of aminophylline 250 mg was calculated for the following dilutions:1054
| Osmolality (mOsm/kg) | ||
|---|---|---|
| Diluent | 50 mL | 100 mL |
| Dextrose 5% | 300 | 291 |
| Sodium chloride 0.9% | 327 | 318 |
Aminophylline may be administered by intravenous infusion following dilution or slow direct intravenous injection.1563
Intact vials should be stored at controlled room temperature and protected from light.1563 Containers of aminophylline should be inspected for particulate matter and discoloration prior to use.1563 Do not use if crystals are present.1563
pH Effects
Reports in the literature of aminophylline precipitating in acidic media do not apply to the dilute solutions found in intravenous infusions.1563 Aminophylline should not be mixed in a syringe with other components of an admixture but should be added separately.6; 1563
Because of the alkalinity of aminophylline-containing solutions, drugs known to be alkali labile should be avoided in admixtures.6; 1563
Temperature Effects
Aminophylline under simulated summer conditions in paramedic vehicles was exposed to temperatures ranging from 26 to 38°C over 4 weeks. Analysis found no loss of the drug under these conditions.2562
Light Effects
A study of aminophylline (Squibb) 50 mg/mL found no change in theophylline after 8 weeks of storage with exposure to fluorescent light.1231
Syringes
Aminophylline (Abbott) 5 mg/mL in bacteriostatic water for injection containing benzyl alcohol 0.9% in plastic syringes (Becton Dickinson) exhibited 2 and 3% losses at 4 and 22°C, respectively, after 91 days of storage.1586
Sorption
Aminophylline was shown not to exhibit sorption to polyvinyl chloride (PVC) bags and tubing, polyethylene tubing, Silastic tubing, and polypropylene syringes.536; 606
Filtration
Aminophylline 500 mg/L in dextrose 5% was passed through an Ivex-2 inline filter at a rate of 2 mL/min. No decrease in the aminophylline concentration occurred over the 8-hour study period.556
Central Venous Catheter
Aminophylline (Abbott) 2.5 mg/mL in dextrose 5% was found to be compatible with the ARROWg+ard Blue Plus (Arrow International) chlorhexidine-bearing triple-lumen central catheter. Essentially complete delivery of the drug was found with little or no drug loss occurring. Furthermore, chlorhexidine delivered from the catheter remained at trace amounts with no substantial increase due to the delivery of the drug through the catheter.2335
For a list of references cited in the text of this monograph, search the monograph titled References.