Distribution of pellets in the gastrointestinal tract. The influence on transit time exerted by the density or diameter of pellets

Abstract

The influence on transit time exerted by the density or diameter of pellets has been established in six ileostomy subjects. An increase in density from 1·0 to 1·6 significantly increased the average transit time of pellets in the small intestine. The average transit time for the light and heavy pellets being 7 and 25 h respectively. The diameter of pellets is of minor significance. The findings suggest the use of density as a means of modifying the period of absorption of controlled‐release pellets.

Floating drug delivery systems: A review

“…As the units of multiparticulate systems are distributed freely throughout the gastrointestinal tract, their transport is affected to a lesser extent by the transit time of food compared with single unit formulation. 20 Size and shape of dosage unit also affect the gastric emptying. Garg and Sharma 21 reported that tetrahedron-and ring-shaped devices have a better gastric residence time as compared with other shapes.…”

Formulation and evaluation of glipizide floating-bioadhesive tablets

“…Extended-release dosage forms with prolonged residence times in the stomach are highly desirable for the drugs with narrow absorption windows, stability problems in the intestinal or colonic environments, locally acting in the stomach, and poor solubility in the intestine (Streubel, Siepmann, and Bodmeier 2003). Recent approaches to increase the gastric residence time of drug delivery systems include bioadhesive devices (Alvisi et al 1996;Ponchel and Irache 1998;Patel and Chavda 2009), swelling devices that increase their size (Urquhart and Theeuwes 1984;Mamajek 1980), low density devices (Streubel et al 2003;and Raval et al 2007), floating systems (Deshpande et al 1997 andDave et al 2004), high density systems (Bechgaard and Ladefoged 1978;Davis et al 1986), magnetic systems, unfoldable and expandable systems, magnetic systems, superporous, biodegradable hydrogel systems (Singh et al 2000) and microparticulate systems (Patel and Chavda 2009). The otherwise-excellent concept of floating system suffers from a disadvantage that it is effective only when the fluid level in the stomach is sufficiently high.…”

Formulation and characterization of gastroretentive drug delivery system of losartan potassium

“…Various approaches that have been reported in the literature for the formulation of gastroretentive systems: mucoadhesion, (Ponchel et al, 1998;Lanerts et al, 1990) flotation, (Deshpande et al1997) sedimentation, (Rednick et al, 1970;Davis et al,1986) expansion (Urguhart et al, 1994;Mamajel et al, 1980) and modified shape systems (Fix et al, 1993;Kedzierewicz et al, 1999). Both single unit systems and multiple unit systems have been reported in the literature (Bechgaard et al, 1978). Floating drug delivery systems also called hydrodynamic balanced system is an effective technology to prolong the gastric residence time in order to improve the bioavailability of the drug (Bardonnet et al, 2006).…”