78 research outputs found
A hydraulically driven colonoscope
BACKGROUND: Conventional colonoscopy requires a high degree of operator skill and is often painful for the patient. We present a preliminary feasibility study of an alternative approach where a self-propelled colonoscope is hydraulically driven through the colon. METHODS: A hydraulic colonoscope which could be controlled manually or automatically was developed and assessed in a test bed modelled on the anatomy of the human colon. A conventional colonoscope was used by an experienced colonoscopist in the same test bed for comparison. Pressures and forces on the colon were measured during the test. RESULTS: The hydraulic colonoscope was able to successfully advance through the test bed in a comparable time to the conventional colonoscope. The hydraulic colonoscope reduces measured loads on artificial mesenteries, but increases intraluminal pressure compared to the colonoscope. Both manual and automatically controlled modes were able to successfully advance the hydraulic colonoscope through the colon. However, the automatic controller mode required lower pressures than manual control, but took longer to reach the caecum. CONCLUSIONS: The hydraulic colonoscope appears to be a viable device for further development as forces and pressures observed during use are comparable to those used in current clinical practice
Preclinical electrogastrography in experimental pigs
Surface electrogastrography (EGG) is a non-invasive means of recording gastric myoelectric activity or slow waves from cutaneous leads placed over the stomach. This paper provides a comprehensive review of preclinical EGG. Our group recently set up and worked out the methods for EGG in experimental pigs. We gained our initial experience in the use of EGG in assessment of porcine gastric myoelectric activity after volume challenge and after intragastric administration of itopride and erythromycin. The mean dominant frequency in pigs is comparable with that found in humans. EGG in experimental pigs is feasible. Experimental EGG is an important basis for further preclinical projects in pharmacology and toxicology
Dissolution Profiles of Generic Products in Dissolution Media Defined by Japanese Guidelines for Bioequivalence Studies
Visualizing the Journey of Fenofibrate through the Rat Gastrointestinal Tract by Matrix-Assisted Laser Desorption/IonizationMass Spectrometry Imaging
A fast and green reversed‐phase HPLC method with fluorescence detection for simultaneous determination of amlodipine and celecoxib in their newly approved fixed‐dose combination tablets
In silico Predictions of Drug Solubility and Permeability: Two Rate-limiting Barriers to Oral Drug Absorption
Instability of Misoprostol Tablets Stored Outside the Blister: A Potential Serious Concern for Clinical Outcome in Medical Abortion
Oral bioavailability in pigs of a miconazole/Hydroxypropyl-γ-cyclodextrin/ L-tataric acid inclusion complex produced by supercritical carbon dioxide processing
The objective of this study was to determine the pharmacokinetic parameters of miconazole after oral administration of a miconazole/hydroxypropyl-γ-cyclodextrin(HPγCD)/ L-tartaric acid inclusion complex produced by supercritical carbon dioxide processing. The pharmacokinetics of the miconazole ternary complex (CPLX), of the corresponding physical mixture (PHYS), and of miconazole alone (MICO) were compared after oral administration. Six mixed-breed pigs received each formulation as a single dose (10 mg miconazole/kg) in a crossover design. Miconazole plasma concentrations were determined by a high-performance liquid chromatography method. Preliminary in vitro dissolution data showed that CPLX exhibits a faster and higher dissolution rate than either PHYS or MICO. Following CPLX oral administration, mean area under the plasma concentration curve (AUC0−∞) for miconazole was 95.0±55.8 μg/min/mL, with the peak plasma concentration (Cmax 0.59±0.39 μg/mL) at 19.30 minutes. The AUC0−∞ and Cmax values were significantly higher than those after oral administration of PHYS (AUC0−∞ 38.5±12.7 μg/min/mL and Cmax 0.24±0.08 μg/mL;P<.1) and of MICO (AUC0−∞ 24.1±14.0 μg/min/mL and Cmax 0.1±0.05 μg/mL;P<.1). There were also significant differences between PHYS and MICO (P<.1). The results of the study indicate that CPLX shows improved dissolution properties and a higher relative oral bioavailability compared with PHYS and MICO
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