Delayed-release oral suspension of omeprazole for the treatment of erosive esophagitis and gastroesophageal reflux disease in pediatric patients: a review

Spectrophotometric Determination of Aspirin and Omeprazole in the presence of Salicylic Acid as a Degradation Product: A Comparative Evaluation of Different Univariate/Multivariate Post Processing Algorithms

BACKGROUND

A recent combination of aspirin (ASP) and omeprazole (OMP) has been presented in a fixed dosage form for treatment of many CVD, particularly in patients with gastric diseases. However, ASP is very sensitive to degradation into salicylic acid (SAL) as its main degradation product. Hence, it is very important to develop methods for the determination of ASP and OMP in the presence of SAL.

OBJECTIVE

In this study, UV spectrophotometry assisted by different univariate/multivariate post processing algorithms have been presented for quantitative determination of ASP, OMP and SAL without any prior separation.

METHODS

The univariate/multivariate algorithms include double divisor ratio difference and double divisor mean centering as the univariate approaches while the multivariate methods include principal component regression (PCR) and partial least squares (PLS) models. Validation of the univariate methods was done according to the ICH guidelines while the multivariate models were validated using external validation set.

RESULTS

The univariate algorithms displayed excellent regression and validation capabilities in terms of linearity, accuracy, precision, and selectivity. Regarding PCR and PLS, the number of latent variables were carefully optimized, and the model's validation criteria displayed excellent recoveries and lower errors of prediction.

CONCLUSION

Our findings indicate that the developed methods were comparable to the only reported chromatographic methods but with much shorter analysis time and simplicity.

HIGHLIGHTS

Overall, this report presents the first spectrophotometric methods applied for determination of possible combination of ASP, OMP, and SAL, and poses theses methods as valuable analytical tools in in-process testing and quality control analysis.

The role of aldosterone inhibitors in cardiac ischemia-reperfusion injury

Myocardial ischaemia-reperfusion (I/R) injury is a well-known term for exacerbation of cellular destruction and dysfunction after the restoration of blood flow to a previously ischaemic heart. A vast number of studies that have demonstrated that the role of mineralocorticoids in cardiovascular diseases is based on the use of pharmacological mineralocorticoid receptor (MR) antagonists. This review paper aimed to summarize current knowledge on the effects of MR antagonists on myocardial I/R injury as well as postinfarction remodeling. Animal models, predominantly the Langendorff technique and left anterior descending coronary artery occlusion, have confirmed the potency of MR antagonists as preconditioning and postconditioning agents in limiting infarct size and postinfarction remodeling. Several preclinical studies in rodents have established and proved possible mechanisms of cardioprotection by MR antagonists, such as reduction of oxidative stress, reduction of inflammation, and apoptosis, therefore limiting the infarct zone. However, the results of some clinical trials are inconsistent, since they reported no benefit of MR antagonists in acute myocardial infarction. Due to this, further studies and the results of ongoing clinical trials regarding MR antagonist administration in patients with acute myocardial infarction are being awaited with great interest.

Effects of ischemia and omeprazole preconditioning on functional recovery of isolated rat heart

OBJECTIVE

The aim of this study was to compare protective effects of ischemic and potential protective effects of pharmacological preconditioning with omeprazole on isolated rat heart subjected to ischemia/reperfusion.

METHODS

The hearts of male Wistar albino rats were excised and perfused on a Langendorff apparatus. In control group (CG) after stabilization period, hearts were subjected to global ischemia (perfusion was totally stopped) for 20 minutes and 30 minutes of reperfusion. Hearts of group II (IPC) were submitted to ischemic preconditioning lasting 5 minutes before 20 minutes of ischemia and 30 minutes of reperfusion. In third group (OPC) hearts first underwent preconditioning lasting 5 minutes with 100 μM omeprazole, and then submitted 20 minutes of ischemia and 30 minutes of reperfusion.

RESULTS

Administration of omeprazole before ischemia induction had protective effect on myocardium function recovery especially regarding to values of systolic left ventricular pressure and dp/dt max. Also our findings are that values of coronary flow did not change between OPC and IPC groups in last point of reperfusion.

CONCLUSION

Based on our results it seems that ischemic preconditioning could be used as first window of protection after ischemic injury especially because all investigated parameters showed continuous trend of recovery of myocardial function. On the other hand, preconditioning with omeprazole induced sudden trend of recovery with positive myocardium protection, although less effective than results obtained with ischemic preconditioning not withstand, we must consider that omeprazole may be used in many clinical circumstances where direct coronary clamping for ischemic preconditioning is not possible.

Proton pump inhibitors in pediatrics : mechanism of action, pharmacokinetics, pharmacogenetics, and pharmacodynamics

Proton pump inhibitors (PPIs) have become some of the most frequently prescribed medications for treatment of adults and children. Their effectiveness for treatment of peptic conditions in the pediatric population, including gastric ulcers, gastroesophageal reflux disease (GERD), and Helicobacter pylori infections has been established for children older than 1 year. Studies of the preverbal population of neonates and infants have identified doses that inhibit acid production, but the effectiveness of PPIs in the treatment of GERD has not been established except for the recent approval of esomeprazole treatment of erosive esophagitis in infants. Reasons that have been proposed for this are complex, ranging from GERD not occurring in this population to a lack of histologic identification of esophagitis related to GERD to questions about the validity of symptom scoring systems to identify esophagitis when it occurs in infants. The effectiveness of PPIs relates to their structures, which must undergo acidic activation within the parietal cell to allow the PPI to be ionized and form covalent disulfide bonds with cysteines of the H(+)-K(+)-adenosine triphosphatase (H(+)-K(+)-ATPase). Once the PPI binds to the proton pump, the pump is inactivated. Some PPIs, such as omeprazole and rabeprazole bind to cysteines that are exposed, and their binding can be reversed. After irreversible chemical inhibition of the proton pump, such as occurs with pantoprazole, the recovery of the protein of the pump has a half-life of around 50 h. Cytochrome P450 (CYP) 2C19 and to a lesser degree CYP3A4 clear the PPIs metabolically. These enzymes are immature at birth and reach adult levels of activity by 5-6 months after birth. This parallels studies of the maturation of CYP2C19 to adult levels by roughly the same age after birth. Specific single nucleotide polymorphisms of CYP2C19 reduce clearance proportionally and increase exposure and prolong proton pump inhibition. Prolonged treatment of pediatric patients with PPIs has not caused cancer or significant abnormalities.

Gastro-esophageal reflux disease in healthy older children and adolescents

Gastro-esophageal reflux disease (GERD) in otherwise healthy older children and adolescents is commonly encountered in pediatric clinics and poses a complex treatment problem involving changes of diets and lifestyle. After an initial history taking and a physical examination, typical symptoms of GERD in older children and adolescenct are initially treated with the trials of acid suppressants. With an increase of severe cases, more and more GERD children have been evaluated with endoscopy, which helps to delineate an erosive esophagitis from a non-erosive reflux disease as they are presumed to have different pathogenesis. For the pediatric patients without a significant underlying disease, a reflux esophagitis can be treated adequately with acid suppressants. Recently, the rapid increase of children who are taking anti-reflux medication has brought up a serious alarm among pediatricians. Some at risk pediatric patients with recurrent and/or chronic GERD have been linked to adulthood GERD. In this paper, pediatric GERD with and without erosive esophagitis was reviewed along with treatment options and issues specifically for the otherwise healthy older children and adolescents in the primary clinics or the secondary hospitals.