Razvoj i karakterizacija mukoadhezivnih flastera salbutamol sulfata za jednosmjernu bukalnu isporuku

Buccal patches of salbutamol sulfate were prepared using five different water soluble polymers in various proportions and combinations using PEG-400/PG as plasticizers. A 32 full factorial design was used to design the experiments for each polymer combination. Patches were laminated on one side with a water impermeable backing layer for unidirectional drug release. The thickness of medicated patches ranged between 0.2 and 0.4 mm and showed an increase in mass whenever PEG-400 was used as plasticizer. The surface pH of all patches approached neutral. Eight formulations which had shown high folding endurance (> 300) were selected for evaluation. Patches prepared with PEG-400 showed a high swelling index. The residence time of the tested patches ranged between 105 and 130 min. Formulations A10, A32, B10 and B32 fitted the Higuchi model best, whereas formulations A19 and B19 showed super case II transport drug release. Stability studies indicated that there was no change in the chemical and physical characteristics during the test period of 6 months.U radu je opisana priprava flastera za bukalnu primjenu upotrebom različitih omjera pet vodotopljivih polimera i PEG-400/PG kao plastifikatora. Potpuni 32 faktorijalni dizajn upotrebljen je za dizajniranje eksperimenata za svaku kombinaciju polimera. Flasteri su postavljeni na jednu stranu usta s vodonepropusnom podlogom, koja omogućava jednosmjerno oslobađanje lijeka. Debljina flastera varirala je između 0,2 i 0,4 nm. Flasteri s PEG-400 bili su malo veće mase. pH na površini svih flastera bio je blizu neutralnog. Osam pripravaka vrlo otpornih na presavijanje (300) izabrano je za daljnju evaluaciju. Flasteri pripravljeni s PEG 400 imali su veliku sposobnost bubrenja. Flasteri su se zadržali na mjestu primjene između 105 i 130 min. Pripravci A10, A32, B10 i B32 najbolje su slijedili Higuchijev model, dok su pripravci A19 i B19 pokazivali anomalno oslobađanje koje ne slijedi Fickov zakon. Ispitivanje stabilnosti pokazalo je da ne postoje promjene u kemijskim i fizikalnim svojstvima pripravaka tijekom 6 mjeseci

Regional transport and metabolism of roivacaine and its CYP3A4 metabolite PPX in human intestine

The major aim of this study was to investigate the CYP3A4 metabolism and polarized transport of ropivacaine and its metabolite 2',6'-pipecoloxylidide (PPX) in tissue specimens from the human small and large intestine. Ropivacaine has been shown to be effective in the treatment of ulcerative colitis in human colon. This study was conducted using a modified Ussing-chamber technique with specimens from jejunum, ileum and colon collected from 11 patients. The local kinetics of ropivacaine and PPX were assessed from their concentration-time profiles in mucosal and serosal compartments. The permeability (P-app) in the absorptive direction for both ropivacaine and PPX increased regionally in the order jejunum <ileum<colon. Ropivacaine was not found to be subjected to any carrier-mediated intestinal efflux. However, the CYP3A4 metabolite left the human enterocyte in a polarized manner and both the extent of CYP3A4 metabolism of ropivacaine and the extrusion of its metabolite to the mucosal chamber were more efficient in jejunum than in ileum. P-glycoprotein was probably not involved in the metabolite extrusion. No other metabolite than PPX was found. This in-vitro study with human intestinal tissues provides new mechanistic insights into regional transport and metabolism of drugs