Absorption food effects

Utilize lymphatic Increase absorption Food effects persist for longer... 

B. J. Aungst, N. H. Nguyen, N. J. Taylor, D. S. Bindra. Formulation and food effects on the oral absorption of a poorly water soluble, highly permeable antiretroviral agent. J. Pharm. Sci. 2002, 91, 1390-1395. 

Tab. 21.6. Potential food effects on drug absorption for BCS class I—III drugs.

In this case, the solubility is extremely poor, even at pH 7, which is considerably above the pKa of troglitazone and corresponds to pH values commonly found in the mid section of the small intestine. Other well-known compounds with analogous behavior are mefenamic acid, glyburide, and phe-nytoin. For troglitazone, the presence of bile salts improves the solubility quite dramatically and lipophilic constituents in the dissolution medium (e.g., in full-fat milk) lead to better dissolution, and in turn better absorption when troglitazone is administered in the fed than the fasted state, as reported by Nicolaides (13). Use of biorelevant dissolution testing permitted these authors not only to qualitatively predict the food effect, but also to predict relative bioavailability of three test formulations. 

The fed and fasted state may also have significant effects on the absorption or solubility of a compound. Compositions of media that simulate the fed and fasted states can be found in the literature (19) (see also Chapter 5). These media reflect changes in the pH, bile concentrations, and osmolarity after meal intake and therefore have a different composition than that of typical compendial media. They are primarily used to establish in vitro-in vivo correlations during formulation development and to assess potential food effects and are not intended for quality control purposes. For quality control purposes, the substitution of natural surfactants (bile components) with appropriate synthetic surfactants is permitted and encouraged because of the expense of the natural substances and the labor-intensive preparation of the biorelevant media. 

Investigation of potential food effects on drug absorption. 

Investigation of Potential Food Effects on Drug Absorption... 

Consequently, the interplay between solubility and permeability with too many free variables is hindering the researcher or developer from clear statements. Interactions of food with oral absorption may happen at different stages, which again can be titled as dissolution and permeation, and a combined dissolution and permeation assessment might give a deeper insight into possible interaction and food effects. 

Food effect Delays time to peak concentration does not alter extent of absorption 28% decrease in C ax > 1 delay in T ax ( I h) no overall change in AUC... 

Like fluconazole, voriconazole (Muijsers et al., 2002) is polar, with moderate aqueous solubility (0.5 mg/mL), resulting in rapid absorption (maximum concentration achieved in less than 2 h) and oral bioavailability (96%). Moderate food effects have been observed. Distribution is wide with a steady-state volume of 4.6L/kg and moderate binding to plasma proteins (58%). 

Food effect, absorption of most psychotropic drugs is not significantly affected by concomitant intake of food. An exception is buspirone, with a twofold increase of absorption with food intake... 

However, the food-effect study on Sporaffooral solution in healthy subjects observed that oral bioavailability of itraconazole actually decreased by 31 % under fed condition (Van de Velde et al., 1996). Thus, in its product labeling, it is indicated that SporShoral solution should be taken without a meal to ensure maximal absorption. Further, Spof Dcad solution and capsules should not be used interchangeably. 

S. Shelukar, G Kwei, and D. Storey (2004). The role of biopharmaceutics in the development of a clinical nanoparticle formulation of MK-0869 a beagle dog model predicts improved bioavailability and diminished food effect on absorption in humlait). J. Pharm, 285 135-146. 

Food-Effect Studies. Coadministration of food with oral drug products may influence drug BA and/or BE. Food-effect BA studies focus on the effects of food on the release of the drug substance from the drug product as well as the absorption of the drug substance. BE studies with food focus on demonstrating comparable BA between test and reference products when coadministered with meals. Usually, a single-dose, two-period, two-treatment, two-sequence crossover study is recommended for both food-effect BA and BE studies. 

FOOD EFFECTS The effects of food on zinc absorption are important and particularly pertinent to the topic of this symposium. Generally, food appears to interfere with zinc absorption. Three subjects who had eaten breakfast one to three hours prior to receiving Zn-65 absorbed a mean of 17% of the administered activity with values ranging from 9 to 31%. Absorption by these three non-fasting subjects averaged about one quarter that of the 75 fasting subjects studied in the same manner. 

The complexity of food effects on zinc absorption is illustrated by the studies of Sandstrom et al.(25,37,38) in which phytate, protein, calcium, zinc and other factors appear to have variable effects on zinc absorption. Although It appears certain that food interferes with zinc absorption, the effects of individual food substances are unknown and difficult to predict. Regardless of individual effects, zinc administration with food will complicate efforts to measure the effects of other variables on intestinal absorption. 

Factors affecting drug absorption include formulation, disease state, food effect, and drug-drug interaction. Formulations used for oral administration include solutions, suspensions, capsules, and uncoated and coated tablets. Depending on the formulation of a drug, the absorption characteristics may differ substantially. 

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