The effect of food on the systemic availability of ketoprofen

Mathematical Modeling of the Gastrointestinal System for Preliminary Drug Absorption Assessment

The objective of this study is to demonstrate the potential of a multicompartmental mathematical model to simulate the activity of the gastrointestinal system after the intake of drugs, with a limited number of parameters. The gastrointestinal system is divided into five compartments, modeled as both continuous systems with discrete events (stomach and duodenum) and systems with delay (jejunum, ileum, and colon). The dissolution of the drug tablet occurs in the stomach and is described through the Noyes-Whitney equation, with pH dependence expressed through the Henderson-Hasselbach relationship. The boluses resulting from duodenal activity enter the jejunum, ileum, and colon compartments, where drug absorption takes place as blood flows countercurrent. The model includes only three parameters with assigned physiological meanings. It was tested and validated using data from in vivo experiments. Specifically, the model was tested with the concentration profiles of nine different drugs and validated using data from two drugs with varying initial concentrations. Overall, the outputs of the model are in good agreement with experimental data, particularly with regard to the time of peak concentration. The primary sources of discrepancy were identified in the concentration decay. The model's main strength is its relatively low computational cost, making it a potentially excellent tool for in silico assessment and prediction of drug adsorption in the intestine.

Evaluating Utilization of Tiny-TIM to Assess the Effect of Food on the Absorptions of Oral Drugs and Its Application on Biopharmaceutical Modeling

Safety and efficacy are the most critical factors for the development of modern medications. For oral drugs, evaluating drug exposure under various conditions is one of the most important outcomes for clinical trials. These data will help to better understand the safety and efficacy of new drugs. Studies involving potential drug-drug interactions, proton pump inhibitors, and intake of food are often conducted to assess the above. Among the above, the influence of food on exposure to the drug is one of the key data sets for regulatory submission. Since food may have either a positive or negative effect on drug exposure, it is important to obtain an early assessment of the food effect. To better forecast and plan for clinical studies, substantial efforts have been made in the industry to develop modeling and in-vitro and in-vivo assays. Despite the efforts, predicting the effect of food on exposure without integrating the dynamic of the gastrointestinal tract in the assessment remains challenging. In this study, we evaluated the utilization of the dynamic Gastro-Intestinal Model (Tiny-TIM) for the food effect of over 20 drugs/formulations in development or on the market that covers all BCS classes. In general, the Tiny-TIM predicted food effects were in good agreement with the reported data in humans. This suggests that Tiny-TIM can successfully capture the impact of physicochemical properties on absorption under the influence of food.

Effects of Ingested Water Volume on Oral Absorption of Fenofibrate, a BCS Class II Drug, from Micronized and Amorphous Solid Dispersion Formulations in Rats

In this study, we investigated the effects of ingested water volume on the oral absorption of fenofibrate (FEN) with several formulations to confirm the applicability of rats for oral formulation screening. Oral absorption of suspended crystalline FEN was significantly improved by increasing ingested water volume (from 0.5 to 2 mL). FEN absorption improvement by particle size reduction and the linearity in oral absorption by dose escalation suggested that the rate-limiting step of FEN absorption in rats was the dissolution rate, consistent with that in humans. When FEN, as an amorphous solid dispersion (ASD) formulation, was suspended in water followed by immediate administration, oral FEN absorption was significantly higher than when administered in crystalline form and was not influenced by the differences in ingested water volume. Oral absorption of FEN from encapsulated ASD formulation in 1 or 2 mL of water was comparable with that of the suspension form. However, 0.5 mL of water significantly reduced the oral absorption of the solid ASD FEN formulation. These results indicate that to improve the oral absorption of poorly water-soluble drugs when performing a preclinical study with rats, 1 mL of water is the minimum preferable ingested volume to evaluate in vivo formulation performance.

Population scale retrospective analysis reveals distinctive antidepressant and anxiolytic effects of diclofenac, ketoprofen and naproxen in patients with pain

Currently approved monoamine modulating antidepressant and anxiolytic pharmaceutics fail in over one third of patients due to delayed and variable therapeutic effect, adverse reactions preceding the therapeutic action, and adherence issues. Even with adequate adherence to the regimen and tolerability, one third of the patients do not respond to any class of antidepressants. There is a strong correlation between treatment resistant depression and increase in inflammatory cytokines in plasma and cerebrospinal fluid. Furthermore, epidemiological studies suggest that depression and anxiety are commonly comorbid with pain and inflammation. While a link between pain, inflammation and depression has been suggested it remains unclear which anti-inflammatory treatment may be beneficial to patients with depression and anxiety due to pain. Here, we analyzed 430,783 FDA adverse effect reports of patients treated for pain to identify potential antidepressant and anxiolytic effects of various anti-inflammatory medications. Patients treated for depression or patients taking any known antidepressants were excluded. The odds ratio analysis of 139,072 NSAID reports revealed that ketoprofen was associated with decreased reports of depression by a factor of 2.32 (OR 0.43 and 95% Confidence Interval [0.31, 0.59]) and decreased reports of anxiety by a factor of 2.86 (OR 0.35 [0.22, 0.56]), diclofenac with decreased depression reports by a factor of 2.22 (OR 0.45 [0.40, 0.49]) and anxiety by a factor of 2.13 (OR 0.47 [0.41, 0.54]), while naproxen decreased depression reports by a factor of 1.92 (OR 0.52 [0.49, 0.57]) and anxiety by a factor of 1.23 (OR 0.81 [0.75, 0.88]). Other NSAIDs did not exhibit any noticeable antidepressant and/or anxiolytic effect.

Effects of food on pharmacokinetics of immediate release oral formulations of aspirin, dipyrone, paracetamol and NSAIDs - a systematic review

Aims

It is common to advise that analgesics, and especially non-steroidal anti-inflammatory drugs (NSAIDs), be taken with food to reduce unwanted gastrointestinal adverse effects. The efficacy of single dose analgesics depends on producing high, early, plasma concentrations; food may interfere with this. This review sought evidence from single dose pharmacokinetic studies on the extent and timing of peak plasma concentrations of analgesic drugs in the fed and fasting states.

Methods

A systematic review of comparisons of oral analgesics in fed and fasting states published to October 2014 reporting kinetic parameters of bioavailability, time to maximum plasma concentration (t_max), and its extent (C_max) was conducted. Delayed-release formulations were not included.

Results

Bioavailability was not different between fasted and fed states. Food typically delayed absorption for all drugs where the fasting t_max was less than 4 h. For the common analgesics (aspirin, diclofenac, ibuprofen, paracetamol) fed t_max was 1.30 to 2.80 times longer than fasted t_max. C_max was typically reduced, with greater reduction seen with more rapid absorption (fed C_max only 44–85% of the fasted C_max for aspirin, diclofenac, ibuprofen and paracetamol).

Conclusion

There is evidence that high, early plasma concentrations produces better early pain relief, better overall pain relief, longer lasting pain relief and lower rates of remedication. Taking analgesics with food may make them less effective, resulting in greater population exposure. It may be time to rethink research priorities and advice to professionals, patients and the public.

Effect of food on systemic exposure to niflumic acid following postprandial administration of talniflumate

PURPOSE

Talniflumate was designed as a prodrug of niflumic acid, a potent analgesic and anti-inflammatory drug, which is widely prescribed for treating rheumatoid diseases. The prandial effect on talniflumate absorption remains unclear; therefore, this study investigated the effect of food on the systemic exposure to niflumic acid in healthy volunteers.

METHODS

Volunteers received a single 740-mg dose of talniflumate 30 min after consuming a high-fat breakfast, a low-fat breakfast, or no food (fasting condition). Plasma concentrations of both talniflumate and niflumic acid were measured using validated high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

The maximum concentration of niflumic acid was 224 +/- 193 ng/ml at approximately 2.7 h in the fasted condition compared with 886 +/- 417 ng/ml (p < 0.05) at 1.8 h and 1,159 +/- 508 ng/ml (p < 0.01) at 2.2 h with the low- and high-fat meals, respectively. The mean area under the curve from zero to infinity (AUC(inf)) values after the low- and high-fat meals were four- and fivefold, respectively, the value while fasting (p < 0.05).

CONCLUSIONS

It is strongly recommended that talniflumate be taken after a meal to increase systemic exposure to its active metabolite. Our results suggest a reduction in the daily dosage of talniflumate when taken with food.

Effect of food intake on the oral absorption of poorly water-soluble drugs: in vitro assessment of drug dissolution and permeation assay system

The aim of the present work was to establish appropriate conditions for the dissolution/permeation system (D/P system) to estimate the effect of food intake on oral drug absorption. The D/P system is an in vitro assay system to evaluate the drug dissolution and permeation processes after oral administration. Caco-2 monolayer was used as a model membrane of the intestinal epithelium. In this study, two types of simulated intestinal fluid reflecting the fasted and the fed state conditions of the human gastrointestinal tract were used. Drugs were applied to the D/P system as a powder, then, permeated amounts of drugs into the basal side were monitored. A sigmoidal correlation was obtained between in vivo oral absorption (% absorbed of dose) and in vitro permeated amount (% of dose/2 h) under both states. From the D/P system, the estimated absorption of albendazole in both states was found to correspond well with in vivo observation. Moreover, the D/P system could estimate the effect of self-emulsifying formulation on the oral absorption of danazol, quantitatively. In conclusion, the D/P system was proved to be a useful assay system not only for the oral absorption of drugs, but also for the food effect on the absorption.

Bioavailability of a new ketoprofen formulation for once-daily oral administration

A new sustained-release formulation (sustained release Ibifen) that gradually releases ketoprofen within 24 h and ensures therapeutic plasma concentration for the entire period has been developed. It consists of tableted pH-dependent barrier film-coated ketoprofen granules and was administered at a single dose of 200 mg to 12 volunteers. Ketoprofen plasma profiles were compared with: (1) administration of Orudis retard 200 capsule (200 mg); (2) two 12-h doses of prompt release Ibifen capsules (100 mg). In vitro dissolution kinetics and ketoprofen plasma levels were measured by HPLC. Sustained release Ibifen dissolution rate was constant for 10 h, whereas Orudis retard 200 dissolution profile presented one higher slope (0-6 h) and a lower one (6-12 h). Both formulations showed a delayed kinetics with respect to prompt release Ibifen. After sustained release Ibifen administration, ketoprofen plasma peak, reached within 2 h, remained practically constant for at least 12 h (average 4 microg/ml), which is higher than therapeutic levels. Differently, Orudis retard 200 produced a delayed, higher C(max) (5.91+/-0.66 vs. 4.51+/-0.65 microg/ml; P<0.01) and disappeared more quickly. In conclusion, sustained release Ibifen can ensure therapeutic ketoprofen plasma levels for the entire 24 h period, avoiding plasma concentration spikes, with bioavailability similar to other ketoprofen preparations.

Human variability in glucuronidation in relation to uncertainty factors for risk assessment

The appropriateness of the default uncertainty factor for human variability in kinetics has been investigated for glucuronidation using an extensive database of substrates metabolised primarily by this pathway. Inter-individual variability was quantified for 15 compounds from published pharmacokinetic studies (after oral and intravenous dosing) in healthy adults and other subgroups using parameters relating to chronic exposure (metabolic and total clearances, area under the plasma concentration time-curve (AUC)) and acute exposure (C(max)). Low inter-individual variability (about 30-35%) was found for all parameters (clearance corrected or not corrected for body weight, metabolic clearance, oral AUC and C(max)) after either iv or oral administration to healthy adults. The overall variability of 31% for glucuronidation in healthy adults supported the validity of the default kinetic uncertainty factor of 3.16 for this group, because it would cover more than 99% of individuals. Comparisons between potentially sensitive subgroups and healthy adults using differences in means and variability indicated that neonates showed the greatest impairment of glucuronidation, and that the 3.16 kinetic default factor applied to the mean data for adults would be inadequate for this subpopulation. The in vivo data have been used to derive pathway-related default factors for compounds eliminated largely via glucuronidation.

Clinical Pharmacokinetics of Dexketoprofen

Dexketoprofen trometamol is a water-soluble salt of the dextrorotatory enantiomer of the nonsteroidal anti-inflammatory drug (NSAID) ketoprofen. Racemic ketoprofen is used as an analgesic and an anti-inflammatory agent, and is one of the most potent in vitro inhibitors of prostaglandin synthesis. This effect is due to the (S)-(+)-enantiomer (dexketoprofen), while the (R)-(-)-enantiomer is devoid of such activity. The racemic ketoprofen exhibits little stereoselectivity in its pharmacokinetics. Relative bioavailability of oral dexketoprofen (12.5 and 25mg, respectively) is similar to that of oral racemic ketoprofen (25 and 50mg, respectively), as measured in all cases by the area under the concentration-time curve values for (S)-(+)-ketoprofen. Dexketoprofen trometamol, given as a tablet, is rapidly absorbed, with a time to maximum plasma concentration (tmax) of between 0.25 and 0.75 hours, whereas the tmax for the (S)-(+)-enantiomer after the racemic drug, administered as tablets or capsules prepared with the free acid, is between 0.5 and 3 hours. The drug does not accumulate significantly when administered as 25mg of free acid 3 times daily. The profile of absorption is changed when dexketoprofen is ingested with food, reducing both the rate of absorption (tmax) and the maximal plasma concentration. Dexketoprofen is strongly bound to plasma proteins, particularly albumin. The disposition of ketoprofen in synovial fluid does not appear to be stereoselective. Dexketoprofen trometamol is not involved in the accumulation of xenobiotics in fat tissues. It is eliminated following extensive biotransformation to inactive glucuroconjugated metabolites. No (R)-(-)-ketoprofen is found in the urine after administration of dexketoprofen, confirming the absence of bioinversion of the (S)-(+)-enantiomer in humans. Conjugates are excreted in urine, and virtually no drug is eliminated unchanged. The analgesic efficacy of the oral pure (S)-(+)-enantiomer is roughly similar to that observed after double dosages of the racemic compound. At doses above 7mg, dexketoprofen was significantly superior to placebo in patients with moderate to severe pain. A dose-response relationship between 12.5 and 25mg could be seen in the time-effects curves, the superiority of the 25mg dose being more a result of an extended duration of action than of an increase in peak analgesic effect. A plateau in the analgesic activity of dexketoprofen trometamol at the 25mg dose is suggested. The time to onset of pain relief appeared to be shorter in patients treated with dexketoprofen trometamol. The drug was well tolerated.