Advancements in Omeprazole Formulations: From Technological Innovation to Release Strategies

Abstract

This chapter reviews data on 72 omeprazole (OME) formulations developed in the past 5 years. The types of OME formulations, the excipients and the methods are analyzed in depth. Data on 72 omeprazole (OME) formulations created over the last 5 years are reviewed in this chapter. A thorough analysis of the many kinds of OME formulations, excipients and techniques is conducted. The release of OME from various formulations, the variables influencing this release, and how it affects the efficacy of the medication are also covered in this chapter. The review seeks to identify significant distinctions and parallels between these formulations and their constituent parts by contrasting the data gathered.

Introduction

Οmeprazole (OME, Figure 1a) and its S-isomer, esomeprazole (Figure 1b), are potent benzimidazole derivatives and antisecretory drugs, which belong to the widely used group of proton pump inhibitors (PPIs) [1]. OME works by inhibiting the critical enzyme H+/K+ ATPase, which is located in the parietal cells of the stomach and is commonly referred as the proton pump. This enzyme plays a crucial role in the final step of gastric acid production, and by inhibiting it, OME effectively reduces gastric acid secretion [2].

Omeprazole’s primary indications include the treatment of gastric [3] and duodenal ulcers, prevention of gastric and duodenal ulcers related to the use of nonsteroidal anti-inflammatory drugs (NSAIDs), and prevention of ulcer recurrence. It is also used for the treatment of symptomatic gastrοesophageal reflux disease (GERD), esophagitis, Barrett’s esophagus and functional dyspepsia. Additionally, omeprazole is a key component in the eradication of Helicobacter pylori infections in peptic ulcer disease and in managing complex hypersecretory syndromes, such as the Zollinger-Ellison syndrome [4].

One of the major pharmaceutical challenges with omeprazole, as with other PPIs, is the stability issue. Οmeprazole is highly sensitive to the acidic environment and degrades rapidly under the stomach conditions [5]. Thus, its orally administered formulations have to be carefully selected, in order to ensure that OME remains intact, while passing through the stomach and is only released in the small intestine, which typically has a more neutral environment. Τo overcome this significant issue, omeprazole is usually formulated with the incorporation of an enteric coating, which prevents premature degradation [6]. Alternative delivery systems, such as oral suspensions and intravenous formulations, have also been developed for children and patients who may face specific difficulties, such as cataposis-related problems [7].

In the last 35 years, since its initial launch in Europe in 1988 and its subsequent introduction to the United States market in 1989 under the brand name Prilosec®, developed by Astra AB company (now named Astra Zeneca®) [8], omeprazole formulations have undergone significant advancements. Numerous innovative formulations have been examined, in order to enhance omeprazole’s characteristics, in terms of stability, release profile and therapeutic efficacy [9]. Furthermore, in recent years, attempts have been made, to explore OME’s full potential and its repurposing profile with respect to other promising therapeutic uses, like cancer treatment [10]. These developments demonstrate not only the drug’s long-standing importance in the field of gastroenterology, but also its long-lasting role in pharmaceutical innovation.