Hospital Pharmacy - October 2020 - 314

844704
research-article2019

HPXXXX10.1177/0018578719844704Hospital PharmacyBoscolo et al

Original Article

Formulation and Stability Study of
Omeprazole Oral Liquid Suspension
for Pediatric Patients

Hospital Pharmacy
2020, Vol. 55(5) 314--322
© The Author(s) 2019
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https://doi.org/10.1177/0018578719844704
DOI: 10.1177/0018578719844704
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Oriana Boscolo1, Francesco Perra1,2, Leandro Salvo1,
Fabián Buontempo1,3, and Silvia Lucangioli1,4

Abstract
Objectives: To develop and to study the physicochemical and microbiological stability of omeprazole liquid oral formulations
used as therapeutic agent in many acid-related disorders, for pediatric use. Furthermore, to optimize and validate a stabilityindicating high-performance liquid chromatography (HPLC) method for the analysis of omeprazole in the studied formulations.
Method: Oral liquid suspensions of omeprazole were prepared at 2 mg/mL using crushed omeprazole pellets (formulation A)
and pure omeprazole (formulation B) with a complete vehicle including humectant, suspending, sweetening, antioxidant, and
flavoring agents. Samples were stored at 4°C and 25°C. Omeprazole content of each formulation was analyzed in triplicate
using micro-HPLC at 0, 3, 7, 14, 30, 60, 90, 120, and 150 days. Other parameters were also determined, such as appearance,
pH, resuspendibility, and viscosity. Microbiological studies were conducted according to the United Stated Pharmacopeia
(USP) guidelines for non-sterile products. Results: Formulation A stayed physicochemical and microbiologically stable at
refrigerated (4°C) conditions during at least 150 days and it only stayed stable during 14 days at 25°C. Formulation B
was stayed physicochemical and microbiologically stable at refrigerated (4°C) conditions at least 90 days, but it is not
recommended to store at 25°C for more than 1 day. Conclusions: Formulation A and formulation B can be stored for at
least 150 and 90 days, respectively, at refrigerated conditions. Formulation A can be stored at room temperature for 14 days.
Both formulations are perfectly suitable for pediatric patients who are usually notable to swallow solid oral formulations. The
proposed analytical method was suitable for the study of stability of different formulations.
Keywords
omeprazole, formulation, stability study, pediatric, acid-related diseases

Introduction
Omeprazole (OMZ) is a substituted benzimidazole (5-methoxy2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfinyl]1H-benzimidazole) (Figure 1), which inhibits gastric acid
secretion.1 OMZ is indicated for the treatment of acid-related
diseases, such as peptic ulcer, gastroesophageal reflux diseases,
and Zollinger-Ellison syndrome.2
Omeprazole is a weak basic, hydrophobic compound, and
it is a prodrug that is converted at low pH levels to a cyclic
reactive sulfonamide, the pharmacologically active form of
OMZ.3
It is well known that the chemical stability of OMZ is a
function of pH. OMZ is rapidly degraded at pH value below
7.4, but it is stable at alkaline condition (pH 9.5).4 For this
reason, OMZ is commercialized as oral dosage form like
enteric-coated tablets or extended-release capsules containing enteric-coated granules or pellets. The enteric coating
protects OMZ from acid degradation in the stomach.5

Omeprazole is extensively used to treat a wide range of
patients, between them pediatric or geriatric ones. In particular, these 2 groups may have difficulties in swallowing entire
capsules or tablets; moreover, adjusting the correct doses is
not possible. Therefore, in this kind of patients, it is convenient to administer oral liquid dosage form like solution or
suspensions.6,7
Previous studies have investigated the chemical stability of
OMZ in extemporaneous formulations. Most of them, OMZ
1

Universidad de Buenos Aires, Argentina
Università degli Studi di Cagliari, Italy
3
Hospital de Pediatría J. P. Garrahan, Buenos Aires, Argentina
4
Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires,
Argentina
2

Corresponding Author:
Silvia Lucangioli, Pharmaceutical Technology Department, Faculty of
Pharmacy and Biochemistry, Universidad de Buenos Aires, Junin 956,
Capital Federal, 1113 CABA, Argentina.
Email: slucangi@ffyb.uba.ar

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