title: Stability and viscosity of a flavored omeprazole oral suspension for pediatric use.
abstract: OBJECTIVE
  The stability and viscosity of preparations of a commercially available, flavored, immediate-release powder for oral suspension (omeprazole-sodium bicarbonate) during refrigerator and room temperature storage were investigated.
  
  
  METHODS
  Omeprazole-sodium bicarbonate 20-mg packets were suspended to initial omeprazole concentrations of 0.6 and 2 mg/mL, and omeprazole-sodium bicarbonate 40-mg packets were suspended to initial omeprazole concentrations of 1.2, 2, 3, and 4 mg/mL. Suspensions were stored at 4 degrees C in darkness (refrigerated) or 22-25 degrees C (room temperature) in light for one week. A third set of suspensions was stored refrigerated for one month. Omeprazole's stability was quantified after 0, 6, 12, 24, 48, and 168 hours in one-week samples and after 0, 7, 14, 21, and 28 days in one-month samples using high-pressure liquid chromatography. Viscosities of refrigerated suspensions were measured after 0, 1, and 7 days.
  
  
  RESULTS
  Refrigerated suspensions retained >98% and >96% of their initial omeprazole concentrations after one week and one month, respectively. Stability of room temperature suspensions was concentration dependent. After one week, the 0.6- and 1.2-mg/mL suspensions retained 87.2% and 93.1% of their respective initial omeprazole concentrations, whereas the 2-, 3-, and 4-mg/mL suspensions retained >97% of their initial omeprazole concentrations. Suspension viscosities varied 10-fold over the concentrations studied, but all were within the viscosity ranges of other commercially available oral suspensions. Prolonged refrigeration did not increase the suspensions' viscosities.
  
  
  CONCLUSIONS
  Omeprazole-sodium bicarbonate suspensions of 0.6-4 mg/mL omeprazole were stored at 4 degrees C in darkness for up to 28 days. The viscosities of refrigerated suspensions did not increase over 7 days. Except for the 0.6 mg/mL preparations, suspensions stored at room temperature in the light retained >90% of their initial omeprazole content after 7 days, despite turning yellow.
authors.affiliation: Department of Surgery, University of Missouri Hospital and Clinics (UMHC), Columbia, MO 65212, USA. burnettj@health.missouri.edu
authors.forename: Jane E
authors.initials: JE
authors.lastname: Burnett
authors.forename: Ethan R
authors.initials: ER
authors.lastname: Balkin
mesh_terms: D000284:Administration, Oral; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D002626:Chemistry, Pharmaceutical; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D004356:Drug Storage; D005079:Excipients / Q000737:chemistry*; D005421:Flavoring Agents / Q000737:chemistry; D006801:Humans; D007223:Infant; D008027:Light; D009853:Omeprazole / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D010349:Patient Compliance; D011208:Powders; D017410:Practice Guidelines as Topic; D012034:Refrigeration; D017693:Sodium Bicarbonate / Q000737:chemistry; D013535:Suspensions; D013696:Temperature; D013997:Time Factors; D014783:Viscosity
chemical_list: D000897:Anti-Ulcer Agents; D005079:Excipients; D005421:Flavoring Agents; D011208:Powders; D013535:Suspensions; D017693:Sodium Bicarbonate; D009853:Omeprazole