Glycopyrrolate is available as a 0.2-mg/mL injection solution with or without preservative.1172; 1173; 1632 Solutions with preservative are available in 1- and 2-mL single-dose vials and 5- and 20-mL multiple-dose vials.1172 Each mL contains glycopyrrolate 0.2 mg with benzyl alcohol 0.9% as a preservative in water for injection and sodium hydroxide and/or hydrochloric acid for pH adjustment.1172
Preservative-free glycopyrrolate injection is available in 1- and 2-mL single-dose vials and 3- and 5-mL prefilled syringes.1173; 1632 Each mL contains glycopyrrolate 0.2 mg in water for injection with hydrochloric acid and/or sodium hydroxide for pH adjustment.1173; 1632 Sodium chloride also may be present.1173
pH
Trade Name(s)
Robinul, GLYRX-PF
Glycopyrrolate may be administered by intravenous or intramuscular injection without dilution.1172 The manufacturer of a preservative-free formulation (GLYRX-PF) states that the drug may be administered by intravenous or intramuscular injection with or without dilution.1173 The drug may also be given via the tubing of a running intravenous infusion of normal saline.1172; 1173
Glycopyrrolate is a clear, colorless solution; intact vials and prefilled syringes should be stored at controlled room temperature.1172; 1173; 1632
pH Effects
The stability of glycopyrrolate in solution is pH dependent. At pH 2 to 3, the drug is very stable. Above pH 6, the stability becomes questionable because of ester hydrolysis. The speed of this hydrolysis is increased with increasing pH. A significant decline in glycopyrrolate stability as the pH is increased above 6 can be seen in Table 1.331
Table 1. Stability of Glycopyrrolate 0.8 mg/L in Dextrose 5% Adjusted to Various pH Values (25°C)
| Admixture pH | Approximate Time for 5% Decomposition (hr) |
|---|---|
| 4 | >48 |
| 5 | >48 |
| 6 | 30 |
| 6.5 | 7 |
| 7 | 4 |
| 8 | 2 |
Because of the low pH of glycopyrrolate, mixtures with alkaline drugs such as barbiturates result in precipitation of the free acid. If the pH of the admixture is increased above 6 by an alkaline additive or solution, rapid ester hydrolysis of the glycopyrrolate results.331
Syringes
Glycopyrrolate (American Regent) 0.1 mg/mL in sodium chloride 0.9% in polypropylene syringes (Sherwood) was physically stable and exhibited little loss in 24 hours stored at 4 and 23°C.2199
Glycopyrrolate (Robins) 0.2 mg/mL packaged as 4 mL of undiluted injection in 6-mL polypropylene syringes (Becton Dickinson) was stored at 4 and 25°C exposed to fluorescent light. The injection remained visually clear, and little loss of glycopyrrolate occurred in 90 days at both storage conditions.2439
For a list of references cited in the text of this monograph, search the monograph titled References.