Phase I study of omeprazole - Single-dose and multiple-dose studies.

Nakashima, Mitsuyoshi; Kanamaru, Mitsutaka; Hashimoto, Hisakuni; Takiguchi, Yoshiharu; Mizuno, Atsuhiro; Kajiho, Tokuaki; T, Oka; Matsuda, Yasuo

doi:10.3999/jscpt.19.667

Cited by 10 publications

(7 citation statements)

References 26 publications

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“…Meanwhile, the Tmax of rabeprazole after breakfast was significantly longer than that in the fasted state. These results were similar to those of previous reports [23,24]. Delayed gastric emptying might result in delayed absorption of rabeprazole.…”

Section: Discussionsupporting

confidence: 83%

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Influence of the Meal and Genotype of CYP2C19 on the Pharmacokinetics of Proton Pump Inhibitors in Healthy Japanese Subjects

Shinkai¹,

Koike²,

Shimada³

et al. 2013

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Objectives: To evaluate the influence of meals on the pharmacokinetics of omeprazole and rabeprazole and to investigate these PPIs with reference to CYP2C19 genotypes in healthy Japanese men. Methods: This was a randomized, open label, four-way crossover study. Twelve healthy Japanese male volunteers received a single oral dose of either 20 mg omeprazole or 10 mg rabeprazole, in the fasted state and after a standardized breakfast. Results: Between the administration of omeprazole in the fasted state and after breakfast, there were no significant differences in Cmax, AUC, Tmax, and half-life. Between the administration of rabeprazole in the fasted state and after breakfast, there were no significant differences in Cmax, AUC and half-life, whereas the Tmax of rabeprazole after breakfast was significantly delayed (2.8 ± 1.0 vs 5.3 ± 1.8 h, respectively; p = 0.006). PMs demonstrated the highest Cmax and AUC after drug intake under the fasting state and after breakfast, and homo EMs showed a significantly delayed Tmax. Conclusion: When a single dose of either PPI was administered, the pharmacokinetics of omeprazole was not affected by the meal, whereas the Tmax of rabeprazole after the meal was significantly delayed.

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Section: Discussionsupporting

confidence: 83%

“…There are some studies that have shown no effect of food intake on the maximum plasma concentrations (Cmax) and AUC of omeprazole or rabeprazole [23,24].…”

Section: Introductionmentioning

confidence: 99%

Influence of the Meal and Genotype of CYP2C19 on the Pharmacokinetics of Proton Pump Inhibitors in Healthy Japanese Subjects

Shinkai¹,

Koike²,

Shimada³

et al. 2013

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“…The estimates of the parameters for the capsule were consistent with the reported values of a study where an enteric coated omeprazole capsule (20 mg dose) was given orally to six fasted Japanese male subjects. 12 In this study, the standard error of the mean for the C max value from the suppository was smaller than that from the capsule, indicating that the pharmacokinetics of the rectal dosage form is more reproducible. The underlying reason or reasons of reduced variability in the rectal administration of omeprazole are unknown.…”

Section: Resultsmentioning

confidence: 74%

Rectal Absorption of Omeprazole from Suppository in Humans

Choi

Chung

Shim

1996

Journal of Pharmaceutical Sciences

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The oral absorption of omeprazole is incomplete, in part due to first-pass metabolism. We investigated the feasibility of rectal administration of omeprazole by comparing its absorption from a Witepsol H15-based rectal suppository and an orally administered commercial gelatin capsule in 10 male volunteers. Profiles of plasma concentration between two preparations (20 mg) were not statistically different, indicating that the rate and the extent of absorption were similar. Paired t-test revealed no significant differences in area under the curve, mean residence time, and time to peak concentration between two preparations. On the other hand, lag time of absorption and peak concentration were statistically different (p< 0.05) between these preparations. Under these experimental conditions, the rectal route did not produce an improvement in the extent of absorption over an oral capsule.

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“…The bioavailability of omeprazole is thought to be influenced by concomitant food intake. However, no significant difference was observed in the acid-suppressive effect of single oral administration of omeprazole 20 mg between before breakfast and after breakfast [27], as well as in the area under the concentration-time curve (AUC) of omeprazole after single oral administration of omeprazole 20 mg between before breakfast and after breakfast [28,29]. From this background, we consider that the results of this study are not different from that if omeprazole had been administered before breakfast.…”

Section: Discussionmentioning

confidence: 80%