3D-Printed Gastroretentive Sustained Release Drug Delivery System by Applying Design of Experiment Approach.

This study aimed to develop a novel oral drug delivery system for gastroretentive sustained drug release by using a capsular device. A capsular device that can control drug release rates from the inner immediate release (IR) tablet while floating in the gastric fluid was fabricated and printed by a fused deposition modeling 3D printer. A commercial IR tablet of baclofen was inserted into the capsular device. The structure of the capsular device was optimized by applying a design of experiment approach to achieve sustained release of a drug while maintaining sufficient buoyancy. The 2-level factorial design was used to identify the optimal sustained release with three control factors: size, number, and height of drug-releasing holes of the capsular device. The drug delivery system was buoyant for more than 24 h and the average time to reach 80% dissolution (T80) was 1.7-6.7 h by varying the control factors. The effects of the different control factors on the response factor, T80, were predicted by using the equation of best fit. Finally, drug delivery systems with predetermined release rates were prepared with a mean prediction error ≤ 15.3%. This approach holds great promise to develop various controlled release drug delivery systems.

Simultaneous analysis of acetylcarnitine, proline, hydroxyproline, citrulline, and arginine as potential plasma biomarkers to evaluate NSAIDs-induced gastric injury by liquid chromatography-tandem mass spectrometry.

Although major adverse effects associated with nonsteroidal anti-inflammatory drugs (NSAIDs) are gastric injury, assessment of NSAIDs-induced gastrointestinal adverse effects is mostly dependent on endoscopy due to the lack of plasma biomarkers. Several amino acids associated with collagenase activity and gastric mucosal mass have been suggested as plasma biomarker candidates for gastric injury. Therefore, this study aimed to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the plasma biomarker candidates, i.e., acetylcarnitine, proline, hydroxyproline, citrulline, and arginine and evaluate their potential as a biomarker for NSAIDs-induced gastric injury. The method utilized simple protein precipitation with methanol and D4-citrulline as an internal standard (IS). The assay resulted in the lower limit of quantification (LLOQ) of 0.1 µg/mL for acetylcarnitine and 1 µg/mL for proline, hydroxyproline, citrulline, and arginine in the surrogate blank plasma. The intra- and inter-day accuracy ranged 82.5-111.2% for acetylcarnitine, 95.4-103.3% for proline, 98.9-106.4% for hydroxyproline, 99.5-103.5% for citrulline, and 87.4-105.3% for arginine. The precision was within 6.17%, 3.63%, 6.20%, 6.31%, and 6.17% for acetylcarnitine, proline, hydroxyproline, citrulline, and arginine, respectively. The developed assay was successfully applied to monitor the changes of the plasma levels of the five amino acids in rats and Beagle dogs following repeated oral administrations of aceclofenac. In rats, plasma concentrations of proline, hydroxyproline, and citrulline were significantly reduced after 4 days of aceclofenac administration compared to the control group. In dogs, plasma concentrations of proline and citrulline were significantly decreased after 7 days of aceclofenac administration compared to those obtained after the first aceclofenac administration. These data indicate that plasma levels of proline, hydroxyproline, and citrulline may be used as quantitative biomarkers of NSAIDs-induced gastric damage. The present assay could also be utilized to monitor the changes of these amino acids as potential indicators for various physiological and pathophysiological conditions.

Regional Absorption of Fimasartan in the Gastrointestinal Tract by an Improved in situ Absorption Method in Rats.

The aim of the present study was to assess the regional absorption of fimasartan by an improved in situ absorption method in comparison with the conventional in situ single-pass perfusion method in rats. After each gastrointestinal segment of interest was identified, fimasartan was injected into the starting point of each segment and the unabsorbed fimasartan was discharged from the end point of the segment. Blood samples were collected from the jugular vein to evaluate the systemic absorption of the drug. The relative fraction absorbed (Fabs,relative) values in the specific gastrointestinal region calculated based on the area under the curve (AUC) values obtained after the injection of fimasartan into the gastrointestinal segment were 8.2% ± 3.2%, 23.0% ± 12.1%, 49.7% ± 11.5%, and 19.1% ± 11.9% for the stomach, duodenum, small intestine, and large intestine, respectively, which were comparable with those determined by the conventional in situ single-pass perfusion. By applying the fraction of the dose available at each gastrointestinal segment following the oral administration, the actual fraction absorbed (F'abs) values at each gastrointestinal segment were estimated at 10.9% for the stomach, 27.1% for the duodenum, 40.7% for the small intestine, and 5.4% for the large intestine, which added up to the gastrointestinal bioavailability (FX·FG) of 84.1%. The present method holds great promise to assess the regional absorption of a drug and aid to design new drug formulations.

Pharmacokinetics and Anti-Gastric Ulceration Activity of Oral Administration of Aceclofenac and Esomeprazole in Rats.

This study examined the effects of esomeprazole on aceclofenac pharmacokinetics and gastrointestinal complications in rats. Aceclofenac alone, or in combination with esomeprazole, was orally administered to male Sprague-Dawley rats. Plasma concentrations of aceclofenac, its major metabolite diclofenac, and esomeprazole were simultaneously determined by a novel liquid chromatography-tandem mass spectrometry method. Gastrointestinal damage was determined by measuring ulcer area and ulcer lesion index of the stomach. Oral administration of aceclofenac induced significant gastric ulceration, which was inhibited by esomeprazole administration. Following concurrent administration of aceclofenac and esomeprazole, overall pharmacokinetic profiles of aceclofenac and metabolic conversion to diclofenac were unaffected by esomeprazole. Aceclofenac metabolism and pharmacokinetics were not subject to significant food effects, whereas bioavailability of esomeprazole decreased in fed compared to fasting conditions. In contrast, the pharmacokinetics of aceclofenac and esomeprazole were significantly altered by different dosing vehicles. These results suggest that co-administration of esomeprazole with aceclofenac may reduce aceclofenac-induced gastrointestinal complications without significant pharmacokinetic interactions. The optimal combination and clinical significance of the benefits of the combination of aceclofenac and esomeprazole need to be further evaluated.