Aim of this work was the evaluation of an oral system (Chronotopic™) designed to achieve time and/or site-specific release. The system consists in a drug-containing core, coated by a hydrophilic swellable polymer which is responsible for a lag phase in the onset of release. In addition, through the application of an outer gastroresistant film, the variability in gastric emptying time can be overcome and a colon-specific release can be sought relying on the relative reproducibility of small intestinal transit time. For this study, cores containing antipyrine as the model drug were prepared by tableting and both the retarding and enteric coatings were applied in fluid bed. The release tests were carried out in a USP 24 paddle apparatus. The in vivo testing, performed on healthy volunteers, envisaged the HPLC determination of antipyrine salivary concentration and a γ-scintigraphic investigation. The in vitro release curves presented a lag phase preceding drug release and the in vivo pharmacokinetic data showed a lag time prior to the detection of model drug in saliva. Both in vitro and in vivo lag times correlate well with the applied amount of the hydrophilic retarding polymer. The γ-scintigraphic study pointed out that the break-up of the units occurred in the colon. The obtained results showed the capability of the system in delaying drug release for a programmable period of time and the possibility of exploiting such delay to attain colon-targeted delivery according to a time-dependent approach.

In vitro and in vivo evaluation of an oral system for time and/or site-specific drug delivery / M.E. Sangalli, A. Maroni, L. Zema, C. Busetti, F. Giordano, A. Gazzaniga. - In: JOURNAL OF CONTROLLED RELEASE. - ISSN 0168-3659. - 73:1(2001), pp. 103-110.

In vitro and in vivo evaluation of an oral system for time and/or site-specific drug delivery

M.E. Sangalli
Primo
;
A. Maroni
Secondo
;
L. Zema;A. Gazzaniga
Ultimo
2001

Abstract

Aim of this work was the evaluation of an oral system (Chronotopic™) designed to achieve time and/or site-specific release. The system consists in a drug-containing core, coated by a hydrophilic swellable polymer which is responsible for a lag phase in the onset of release. In addition, through the application of an outer gastroresistant film, the variability in gastric emptying time can be overcome and a colon-specific release can be sought relying on the relative reproducibility of small intestinal transit time. For this study, cores containing antipyrine as the model drug were prepared by tableting and both the retarding and enteric coatings were applied in fluid bed. The release tests were carried out in a USP 24 paddle apparatus. The in vivo testing, performed on healthy volunteers, envisaged the HPLC determination of antipyrine salivary concentration and a γ-scintigraphic investigation. The in vitro release curves presented a lag phase preceding drug release and the in vivo pharmacokinetic data showed a lag time prior to the detection of model drug in saliva. Both in vitro and in vivo lag times correlate well with the applied amount of the hydrophilic retarding polymer. The γ-scintigraphic study pointed out that the break-up of the units occurred in the colon. The obtained results showed the capability of the system in delaying drug release for a programmable period of time and the possibility of exploiting such delay to attain colon-targeted delivery according to a time-dependent approach.
Colonic drug delivery; Delayed release; HPMC coating; Oral drug delivery system; Pulsatile release
Settore CHIM/09 - Farmaceutico Tecnologico Applicativo
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/180173
Citazioni
  • ???jsp.display-item.citation.pmc??? 15
  • Scopus 152
  • ???jsp.display-item.citation.isi??? 107
social impact