Excipient (pharmacologically inactive substance)
What is Propylene Glycol?
Propylene glycol (CH8O2) is a commonly used drug solubilizer in topical, oral, and injectable medications. It is used as stabilizer for vitamins, and as a water-miscible cosolvent. Propylene glycol has been used for over 50 years in a large variety of applications. As a pharmaceutical additive, propylene glycol is generally regarded as safe. However, in the pediatric population, propylene glycol has been implicated in toxicity. Cases of hyperosmolality from absorption of creams applied to burns have been reported. Contact dermatitis has also occurred with topical application in the pediatric population. Hemolysis, central nervous system depression, hyperosmolality, and lactic acidosis have been reported after intravenous administration. Propylene glycol is metabolized to lactic acid, which may lead to the reported lactic acidosis.
The high concentration of propylene glycol contained in certain intravenous drug products, such as phenytoin, diazepam, digoxin, and etomidate, may induce thrombophlebitis. Rapid infusion of solutions containing high concentrations of propylene glycol-containing drugs has been linked to respiratory depression, arrhythmias, hypotension, and seizures. Seizures and respiratory depression have also occurred in children who have ingested oral solutions containing propylene glycol.
Propylene glycol is also used as moisturizer in cosmetic products and as a dispersant in fragrances. There are many other food and industrial uses for propylene glycol. As a food additive, propylene glycol is on the U.S. Food and Drug Administration (FDA) generally regarded as safe list (not to be confused with ethylene glycol, which is extremely toxic if ingested). According the FDA, as a food additive, propylene glycol is metabolized in the body and is used as a normal carbohydrate source. Long-term use and substantial quantities of propylene glycol (up to five percent of the total food intake) can be consumed without causing toxicity. There is no evidence in the available information on propylene glycol that demonstrates, or suggests a hazard to the public when they are used at levels that are now current or might reasonably be expected in the future.
 Dave RH. Overview of pharmaceutical excipients used in tablets and capsules. Drug Topics (online). Advanstar. 10/24/2008 http://drugtopics.modernmedicine.com/drugtopics/Top+News/Overview-of-pharmaceutical-excipients-used-in-tabl/ArticleStandard/Article/detail/561047. Accessed 08/19/2011
 FDA’s SCOGS database; propylene glycol; SCOGS-Report Number: 27; http://www.fda.gov/Food/FoodIngredientsPackaging/GenerallyRecognizedasSafeGRAS/GRASSubstancesSCOGSDatabase/ucm261045.htm. Accessed March 17, 2012.
Top Medications Containing Propylene Glycol
- Amoxicillin 500 mg (Teva Pharmaceuticals USA)
- Amoxicillin Trihydrate 500 mg (Sandoz Pharmaceuticals Inc.)
- Cephalexin Monohydrate 500 mg (Teva Pharmaceuticals USA)
- Clindamycin Hydrochloride 150 mg (Ranbaxy Pharmaceuticals Inc.)
- Clindamycin Hydrochloride 300 mg (Ranbaxy Pharmaceuticals Inc.)
- Diclofenac Sodium Delayed Release 75 mg (Actavis)
- Fluoxetine Hydrochloride 20 mg (Sandoz Pharmaceuticals Inc.)
- Fluoxetine Hydrochloride 20 mg (Teva Pharmaceuticals USA)
- Gabapentin 300 mg (Actavis Elizabeth LLC)
- HydrOXYzine Pamoate 25 mg (Sandoz Pharmaceuticals Inc.)
- Hydroxyzine Pamoate 25 mg (Teva Pharmaceuticals USA)
- Hydroxyzine Pamoate 50 mg (Sandoz Pharmaceuticals Inc.)
- Hydroxyzine Pamoate 50 mg (Teva Pharmaceuticals USA)
- Indomethacin 50 mg (Mylan Pharmaceuticals Inc.)
- Lyrica 75 mg (Pfizer U.S. Pharmaceuticals Group)
- Lyrica 50 mg (Pfizer U.S. Pharmaceuticals Group)
- Omeprazole 20 mg (Mylan Pharmaceuticals Inc.)
- Phentermine Hydrochloride 37.5 mg (Mutual Pharmaceutical)
- Temazepam 30 mg (Mylan Pharmaceuticals Inc.)
- Temazepam 15 mg (Mylan Pharmaceuticals Inc.)