TY - JOUR
TI - Characterization of Contents of Distal Ileum and Cecum to Which Drugs/Drug Products are Exposed during Bioavailability/Bioequivalence Studies in Healthy Adults
AU - Reppas, C.
AU - Karatza, E.
AU - Goumas, C.
AU - Markopoulos, C.
AU - Vertzoni, M.
JO - Pharmaceutical Research
PY - 2015
VL - 32
TODO - 10
SP - 3338-3349
PB - Springer New York LLC
SN - 0724-8741, 1573-904X
TODO - 10.1007/s11095-015-1710-6
TODO - acylglycerol;  bisacodyl;  chenodeoxycholic acid;  cholesterol;  cholic acid;  deoxycholic acid;  fatty acid;  glycochenodeoxycholic acid;  glycocholic acid;  glycodeoxycholic acid;  phosphatidylcholine;  short chain fatty acid;  taurochenodeoxycholic acid;  taurocholic acid;  ursodeoxycholic acid;  buffer;  drug, adult;  Article;  ascending colon;  bioequivalence;  carbohydrate analysis;  cecum;  colonoscopy;  controlled clinical trial;  controlled study;  crossover procedure;  distal ileum;  drug bioavailability;  human;  human experiment;  ileum;  male;  meal;  normal human;  osmolality;  pH;  physical chemistry;  priority journal;  protein content;  supernatant;  telemetry;  ultracentrifugation;  bioavailability;  cecum;  diet restriction;  food;  ileum;  metabolism;  oral drug administration;  osmolarity;  therapeutic equivalence;  young adult, Administration, Oral;  Adult;  Biological Availability;  Buffers;  Cecum;  Colon, Ascending;  Cross-Over Studies;  Fasting;  Food;  Healthy Volunteers;  Humans;  Hydrogen-Ion Concentration;  Ileum;  Male;  Osmolar Concentration;  Pharmaceutical Preparations;  Therapeutic Equivalency;  Young Adult
TODO - Purpose: Characterize the contents of distal ileum and cecum in healthy adults under conditions simulating the bioavailability/bioequivelance studies of drug products in fasted and fed state. Methods: Twelve males participated in a two-phase crossover study. Phase I: subjects remained fasted overnight plus 4.5 h in the morning prior to colonoscopy. Phase II: subjects remained fasted overnight, consumed breakfast in the morning, and abstain from food until colonoscopy, 4.5 h after breakfast. Upon sampling, volume, pH and buffer capacity were measured; after ultracentrifugation, supernatant was physicochemically characterized and non-liquid particles diameter was measured. Results: In distal ileum, pH is ~8.1 and size of non-liquid particles is ~200 μm, regardless of dosing conditions; in fed state, liquid fraction was lower whereas osmolality and carbohydrate content were higher. In cecum, the environment was similar with previously characterized environment in the ascending colon; in fasted state, size of non-liquid particles is smaller than in distal ileum (~70 μm). Fluid composition in distal ileum is different from cecum, especially in fasted state. Conclusion: Differences in luminal environment between distal ileum and cecum may impact the performance of orally administered products which deliver drug during residence in lower intestine. Dosing conditions affect cecal environment more than in distal ileum. © 2015 Springer Science+Business Media New York.
ER -