In Vivo Evaluation of Dosage Forms: Application of Gamma Scintigraphy to Non-enteral Routes of Administration

Abstract

The trend to deliver drugs to defined areas of the body involves sophisticated carriers systems. In addition to the in vitro drug release profile one must be aware of the in vivo behaviour of the dosage form and the drug. Gamma scintigraphy is an elegant way to gain insights of the actual in vivo distribution pattern of dosage forms. This technique relies on the use of radioactive tracers included into the medicament and selected so as to enable an optimum detection by a gamma ray camera. The choice of a convenient label enables the in vivo determination of the targeting of the formulation administered through a large number of routes. The present paper reviews applications of gamma scintigraphy for the evaluation of dosage forms administered by the parenteral, rectal, buccal, nasal, pulmonary, and ophthalmic routes.

Bioadhesive‐Based Dosage Forms: The Next Generation

“…The three main in vivo techniques to monitor bioadhesion include gamma scintigraphy, 38 isolated loop techniques, 35,39 and transit studies with radiolabeled or fluorescent coupled dosage forms. 10,40 In summary, some of the polymeric structural characteristics necessary for bioadhesion can be summarized as follows: (1) strong hydrogen bonding groups, (2) strong anionic or cationic charges, (3) high molecular weight, (4) chain flexibility, and (5) surface energy properties favoring spreading onto mucus.…”

Evaluation of the Clearance of a Sublingual Buprenorphine Spray in the Beagle Dog Using Gamma Scintigraphy

“…Gamma scintigraphy is a long established technique for non-invasive monitoring of dosages in vivo (20), and its use in the dog has been previously reported for gastrointestinal formulation studies (21)(22)(23). The use of pharmacoscintigraphy to evaluate the clearance of a buprenorphine sublingual spray dose was therefore investigated, with the intention of obtaining information, which could aid in interpretation of pharmacokinetic data obtained from such sublingual studies.…”

Equivalence-by-Design: Targeting In Vivo Drug Delivery Profile

“…For example, gamma scintigraphy or other methods were used to study drug deposition, transit time or tissue distribution from an inhaled dosage form or an orally administered modified release product (86)(87)(88)(89)(90)(91)(92). It can be envisioned that the study of preabsorption kinetics may require a multidisciplinary approach including various fields such as biopharmaceutics, biochemistry, biophysics and/or other relevant areas.…”