Species comparison of enantioselective oral bioavailability and pharmacokinetics of ketoprofen

Stereoselective Pharmacokinetics and Residue Depletion of Praziquantel and Its Metabolites, 4-Hydroxypraziquantel Enantiomers, in Swine

Praziquantel (PZQ) is administered as a racemic mixture during swine production to treat parasitic diseases. Despite its widespread application, the pharmacokinetics, residue depletion, bioactivity, and toxicity of PZQ enantiomers in swine remain largely unknown. In this study, a systematic investigation of the pharmacokinetics, tissue distribution, and residue depletion of PZQ, its major metabolites (trans- and cis-4-OH-PZQ), and their enantiomers was conducted in swine. The findings indicated that PZQ was absorbed and metabolized rapidly. In swine plasma, the concentrations of S-PZQ, S-trans-4-OH-PZQ, and R-cis-4-OH-PZQ were higher than those of their respective enantiomers. The three analytes exhibited significant tissue distribution and stereoselectivity in 10 swine tissues. Notably, the two enantiomers of PZQ demonstrated comparable tissue concentrations except in the liver and lung. Moreover, the concentrations of S-trans-4-OH-PZQ and R-cis-4-OH-PZQ were higher than those of their respective enantiomers in the 10 tissues. This study has significant implications for the development of rational dosing strategies, reducing drug usage, and minimizing side effects, as well as accurately assessing the risks associated with PZQ administration and, by extension, other chiral drugs. Furthermore, it lays a theoretical foundation for the future use of the active enantiomer, R-PZQ.

Plasma proteomic changes in response to surgical trauma and a novel transdermal analgesic treatment in dogs

Assessment of pain responses and inflammation during animal surgery is difficult because traditional methods, such as visual analogue scores, are not applicable while under anaesthesia. Acute phase proteins (APPs), such as C-reactive protein and haptoglobin, that are typically monitored in veterinary research, do not show a significant change until at least 2 h post-surgery and therefore, immediate pathophysiological changes are uncertain. The current study used sequential window acquisition of all theoretical mass spectra (SWATH-MS) to investigate plasma proteome changes that occur immediately following surgery in dogs and also to assess the efficacy of a novel transdermal ketoprofen (TK) formulation. Castration was chosen as surgical model in this study. The procedure was performed on twelve dogs (n = 6 in two groups) and blood samples were collected at 0 h, 1 and 2 h after surgery for proteomic analysis. Following surgery, there was a general downregulation of proteins, including complement C- 3, complement factor B, complement factor D, transthyretin, and proteins associated with lipid, cholesterol, and glucose metabolisms, reflecting the systemic response to surgical trauma. Many of these changes were diminished in the transdermal group (TD) since ketoprofen, a non-steroidal anti-inflammatory drug (NSAID), inhibits prostanoids and the associated chemotactic neutrophil migration to site of tissue injury. SIGNIFICANCE: SWATH-MS Proteomic analysis revealed significant changes in plasma proteins, predominantly involved in early acute phase and inflammatory response at 1 & 2 h after surgery in castrated dogs. Pre-operative application of transdermal ketoprofen formulation had reduced the systemic immune response, which was confirmed by negligible alteration of proteins in transdermal treated group. A key outcome of this experiment was studying the efficacy of a novel transdermal NSAID formulation in dogs.

Pharmacokinetic Evaluation of a Novel Transdermal Ketoprofen Formulation in Healthy Dogs

Dogs undergo various surgical procedures such as castration, ovariohysterectomy, and other orthopedic procedures, which are known to cause inflammation and pain. Non-steroidal anti-inflammatory drugs (NSAIDs) are very effective analgesics for alleviating postoperative pain in veterinary medicine. Ketoprofen is currently approved in Australia and the United States for treating different painful conditions in dogs. This study evaluated the pharmacokinetic parameters of ketoprofen after intravenous (IV) and transdermal (TD) administration in healthy dogs. A novel transdermal ketoprofen (TDK) formulation containing 20% ketoprofen, dissolved in a combination of 45:45% isopropanol and Transcutol, along with 10% eucalyptus oil, was developed and evaluated for in vitro dermal permeation using Franz diffusion cells. A crossover study was then conducted to determine the pharmacokinetic parameters of the formulation in six dogs following IV ketoprofen (1 mg/kg) and TDK (10 mg/kg) administration. A liquid chromatography–mass spectrometry (LC-M/MS) method was used to measure plasma concentrations of ketoprofen over time, and a non-compartmental analysis determined the pharmacokinetic parameters. The mean terminal elimination half-life (T_½ h), AUC_0-t (µg·h/mL), and mean residence time (MRT, h) between IV and TDK groups were 4.69 ± 1.33 and 25.77 ± 22.15 h, 15.75 ± 7.72 and 8.13 ± 4.28 µg·h/mL, and 4.86 ± 1.81 and 41.63 ± 32.33 h, respectively. The calculated bioavailability (F%) was ~7%, with a lag time of 30 min to achieve effective plasma concentrations after the application of TDK.

Developmental Pharmacokinetics and Safety of Ibuprofen and Its Enantiomers in the Conventional Pig as Potential Pediatric Animal Model

Pediatric drug development, especially in disease areas that only affect children, can be stimulated by using juvenile animal models not only for general safety studies, but also to gain knowledge on the pharmacokinetic and pharmacodynamic properties of the drug. Recently, the conventional growing piglet has been suggested as juvenile animal model. However, more studies with different classes of drugs are warranted to make a thorough evaluation whether the juvenile pig might be a suitable preclinical animal model. Ibuprofen is one of the most widely used non-steroidal anti-inflammatory drugs in human. The present study determined the PK parameters, gastro-intestinal and renal safety of 5 mg/kg BW ibuprofen after single intravenous, single oral and multiple oral administration to each time eight pigs (four males, four females) aging 1, 4, 8 weeks and 6–7 months. Oral administration was performed via a gastrostomy button. A jugular catheter was used for intravenous administration and blood sampling. To assess NSAID induced renal toxicity, renal function was evaluated using iohexol and p-aminohippuric acid as markers for glomerular filtration rate and renal plasma flow, respectively. After the trial, necropsy and histology was performed to evaluate macroscopic and microscopic gastro-intestinal as well as renal lesions. Both enantiomers, R-ibuprofen and S-ibuprofen, were determined in plasma using an in-house developed and validated UHPLC-MS/MS method. Pharmacokinetic parameters were estimated using compartmental analysis. Clearance and volume of distribution of total ibuprofen and both enantiomers increased with age as was observed in human. The rate of stereochemical conversion decreased with age. Multiple oral dosing decreased the absolute oral bioavailability and maximum plasma concentration of R-ibuprofen and food consumption did not influence drug absorption. Based on the limited available pediatric literature, the current study might suggest the conventional pig as suitable animal model to evaluate NSAIDs for pediatric use.

The pig as a preclinical model for predicting oral bioavailability and in vivo performance of pharmaceutical oral dosage forms: a PEARRL review

OBJECTIVES

In pharmaceutical drug development, preclinical tests in animal models are essential to demonstrate whether the new drug is orally bioavailable and to gain a first insight into in vivo pharmacokinetic parameters that can subsequently be used to predict human values. Despite significant advances in the development of bio-predictive in vitro models and increasing ethical expectations for reducing the number of animals used for research purposes, there is still a need for appropriately selected pre-clinical in vivo testing to provide guidance on the decision to progress to testing in humans. The selection of the appropriate animal models is essential both to maximise the learning that can be obtained from such experiments and to avoid unnecessary testing in a range of species.

KEY FINDINGS

The present review, provides an insight into the suitability of the pig model for predicting oral bioavailability in humans, by comparing the conditions in the GIT. It also contains a comparison between the bioavailability of compounds dosed to both humans and pigs, to provide an insight into the relative correlation and examples on why a lack of correlation may be observed.

SUMMARY

While there is a general trend towards predicting human bioavailability from pig data, there is considerable variability in the data set, most likely reflecting species specific differences in individual drug metabolism. Nonetheless, the correlation between pigs vs. humans was comparable to that reported for dogs vs. humans. The presented data demonstrate the suitability of the pig as a preclinical model to predict bioavailability in human.

Effect of oral KETOPROFEN treatment in acute respiratory disease outbreaks in finishing pigs

Background

Infection with respiratory pathogens can influence production as well as animal welfare. There is an economical and ethical need to treat pigs that suffer from respiratory diseases. Our aim was the evaluation of the possible effects of oral NSAID medication given in feed in acute outbreaks of respiratory disease in finishing pigs. The short- and long-term impact of NSAID dosing on clinical signs, daily weight gain, blood parameters and behaviour of growing pigs in herds with acute respiratory infections were evaluated. Four finishing pig farms suffering from acute outbreaks of respiratory disease were visited thrice after outbreak onset (DAY 0, DAY 3 and DAY 30). Pigs with the most severe clinical signs (N = 160) were selected as representative pigs for the herd condition. These pigs were blood sampled, weighed, evaluated clinically and their behaviour was observed. After the first visit, half of the pens (five pigs per pen in four pens totalling 20 representative pigs per herd, altogether 80 pigs in four herds) were treated with oral ketoprofen (target dose 3 mg/kg) mixed in feed for three days and the other half (80 pigs) with a placebo. In three of the herds, some pigs were treated also with antimicrobials, and in one herd the only pharmaceutical treatment was ketoprofen or placebo.

Results

Compared to the placebo treatment, dosing of ketoprofen reduced sickness behaviour and lowered the rectal temperature of the pigs. Clinical signs, feed intake or blood parameters were not different between the treatment groups. Ketoprofen treatment was associated with somewhat reduced weight gain over the 30-day follow-up period. Concentration analysis of the S- and R-enantiomers of ketoprofen in serum samples collected on DAY 3 indicated successful oral drug administration.

Conclusions

Ketoprofen mainly influenced the behaviour of the pigs, while it had no effect on recovery from respiratory clinical signs. However, the medication may have been started after the most severe clinical phase of the respiratory disease was over, and this delay might complicate the evaluation of treatment effects. Possible negative impact of ketoprofen on production parameters requires further evaluation.

The pharmacokinetics of oral ketoprofen in patients after gastric resection

BACKGROUND

Total and partial gastric resection may affect the pharmacokinetics of drugs, especially orally administered a few days after surgery. Ketoprofen is a non-steroidal anti-inflammatory drug (NSAID) broadly used to treat postoperative pain, including patients after gastric resection. The aim of the research was to analyse the pharmacokinetics (PK) of orally administered ketoprofen in patients after gastrectomy.

METHODS

The research was carried out on two groups of patients after total (TG; Roux-Y procedure) and partial (PG; Billroth II procedure) gastrectomy. The patients in group TG (n=15; mean [SD] age 61.86 [14.15] years; and BMI 24.20 [3.73] kg/m²) and group PG (n=5; mean [SD] age 62.40 [16.80] years; and BMI 23.98 [3.45] kg/m²) received ketoprofen in a single oral dose of 100mg. The measurement of ketoprofen plasma concentrations was made by means of the HPLC (high performance liquid chromatography) method.

RESULTS

The PK parameters in group TG and PG were as follows: maximum plasma concentration (C_max), 3.42 [0.99] and 4.66 [0.81] mg/l (p=0.0220); area under the plasma concentration-time curve from zero to infinity (AUC_0-∞), 9.12 [2.78] and 9.17 [2.87] mg×h/ml (p=0.9734); area under the first moment curve from zero to the time of infinity (AUMC_0-∞), 25.95 [8.52] and 26.53 [11.43] mg×h²/l (p=0.9056); time to reach maximum concentration (t_max), 0.47 [0.25] and 0.55 [0.27] h (p=0.5327), respectively.

CONCLUSIONS

Lower concentrations of ketoprofen in patients after gastrectomy suggest that it might be necessary to apply higher dose of the analgesic.

Widely used pharmaceuticals present in the environment revealed as in vitro antagonists for human estrogen and androgen receptors

A considerable amount of scientific evidence indicates that a number of pharmaceuticals that could be detected in the environment can contribute towards the development of problems associated with human reproductive systems, as well as those of wildlife. We investigated the estrogenic and androgenic effects of select pharmaceuticals with high production volume and environmental relevance. We examined the receptor-binding activities of these pharmaceuticals in the T47D human cell line using altered secretion of cytokine CXCL12. Functional yeast-luciferase reporter gene assays were also employed to confirm the mechanism of receptor binding by estrogen and androgen. Non-steroidal anti-inflammatory drugs, namely ibuprofen, diclofenac and antiarrhythmic agent amiodarone showed strong anti-estrogenic effects in the T47D cell line. In the yeast-luciferase assay, these anti-inflammatory drugs also demonstrated anti-estrogenic potency and inhibited the E2 response in a concentration-dependent manner. Amiodarone did not exhibit any response in the yeast-luciferase assay; therefore, the endocrine disruption presumably occurred at a different level without directly involving the receptor. All the anti-inflammatory drugs considered in this study, including ketoprofen, naproxen and clofibrate, exhibited a dose-dependent antagonism towards the androgen receptor in the yeast-luciferase assays. Several other drugs, including the stimulant caffeine, did not show any response in the tests that were employed. A risk assessment analysis using 'Hazard Quotient' suggested a potential risk, especially in the cases of ibuprofen, ketoprofen, diclofenac and clofibrate. The results reveal the intrinsic endocrine disrupting nature of several pharmaceuticals and thus could contribute towards explaining a number of adverse health effects on humans and wildlife.

Predictivity of dog co-culture model, primary human hepatocytes and HepG2 cells for the detection of hepatotoxic drugs in humans

Drug induced liver injury (DILI) is a major cause of attrition during early and late stage drug development. Consequently, there is a need to develop better in vitro primary hepatocyte models from different species for predicting hepatotoxicity in both animals and humans early in drug development. Dog is often chosen as the non-rodent species for toxicology studies. Unfortunately, dog in vitro models allowing long term cultures are not available. The objective of the present manuscript is to describe the development of a co-culture dog model for predicting hepatotoxic drugs in humans and to compare the predictivity of the canine model along with primary human hepatocytes and HepG2 cells. After rigorous optimization, the dog co-culture model displayed metabolic capacities that were maintained up to 2 weeks which indicates that such model could be also used for long term metabolism studies. Most of the human hepatotoxic drugs were detected with a sensitivity of approximately 80% (n=40) for the three cellular models. Nevertheless, the specificity was low approximately 40% for the HepG2 cells and hepatocytes compared to 72.7% for the canine model (n=11). Furthermore, the dog co-culture model showed a higher superiority for the classification of 5 pairs of close structural analogs with different DILI concerns in comparison to both human cellular models. Finally, the reproducibility of the canine system was also satisfactory with a coefficient of correlation of 75.2% (n=14). Overall, the present manuscript indicates that the dog co-culture model may represent a relevant tool to perform chronic hepatotoxicity and metabolism studies.

Pharmacokinetics of gamithromycin after intravenous and subcutaneous administration in broiler chickens

Gamithromycin is a new macrolide antibiotic that is only registered for use in cattle to treat respiratory disorders such as bovine respiratory disease. The aim of this study was to determine the pharmacokinetics of gamithromycin in broiler chickens. Gamithromycin (6 mg/kg of BW) was injected intravenously (IV) or subcutaneously (SC) to six 4-wk-old chickens in a parallel study design, and blood was collected at different time points postadministration. Quantification of gamithromycin in plasma was performed using an in-house validated liquid chromatography-tandem mass spectrometry method and the pharmacokinetics analyzed according to a 2-compartmental model. Following IV administration, the mean area under the plasma concentration-time curve (AUC0→∞), and α and β half-life of elimination (t1/2el α and t1/2el β) were 3,998 h•ng/mL, 0.90 h, and 14.12 h, respectively. Similar values were obtained after a SC bolus injection, i.e., 4,095 h•ng/mL, 0.34 h, and 11.63 h, for AUC0→∞, t1/2el α, and t1/2el β, respectively. The mean maximum plasma concentration (889.46 ng/mL) appeared at 0.13 h. Gamithromycin showed a large volume of distribution after IV as well as SC administration, 27.08 and 20.89 L/kg, respectively, and a total body clearance of 1.61 and 1.77 L/h•kg, respectively. The absolute bioavailability was 102.4%, showing that there is a complete absorption of gamithromycin after a SC bolus injection of 6 mg/kg of BW.

In vitro-in vivo correlation for low-clearance compounds using hepatocyte relay method

In vitro-in vivo correlation (IVIVC) of intrinsic clearance in preclinical species of rat and dog was established using the hepatocyte relay method to support high-confidence prediction of human pharmacokinetics for low-clearance compounds. Good IVIVC of intrinsic clearance was observed for most of the compounds, with predicted values within 2-fold of the observed values. The exceptions involved transporter-mediated uptake clearance or metabolizing enzymes with extensive extrahepatic contribution. This is the first assay available to address low clearance challenges in preclinical species for IVIVC in drug discovery. It extends the utility of the hepatocyte relay method in addressing low clearance issues.

Postoperative analgesic effects of dexketoprofen, buprenorphine and tramadol in dogs undergoing ovariohysterectomy

The objective of this study was to compare the postoperative analgesic effects of dexketoprofen, tramadol, and buprenorphine in dogs undergoing ovariohysterectomy. Seventy-five adult female dogs were randomly assigned to receive an intravenous injection (IV) of 1mg/kg of dexketoprofen (D), 0.02 mg/kg of buprenorphine (B) or 2mg/kg of tramadol (T). Pain assessment was performed during 48 h after ovariohysterectomy using a dynamic interactive visual analogue scale (DIVAS) and Glasgow composite measure pain scale (CMPS-SF). Rescue analgesia was required in 43%, 21%, and 5% of dogs in the B, T, and D groups, respectively, with significant differences between B and D (p=0.010) groups. The DIVAS and CMPS-SF values of the B group were significantly higher than those of the T and D groups. The most common undesirable effect was dysphoria in dexketoprofen group. Tramadol and dexketoprofen provide superior postoperative analgesia compared with buprenorphine in dogs undergoing ovariohysterectomy.

Enantiospecific ketoprofen concentrations in plasma after oral and intramuscular administration in growing pigs

Background

Ketoprofen is a non-steroidal anti-inflammatory drug which has been widely used for domestic animals. Orally administered racemic ketoprofen has been reported to be absorbed well in pigs, and bioavailability was almost complete. The objectives of this study were to analyze R- and S-ketoprofen concentrations in plasma after oral (PO) and intra muscular (IM) routes of administration, and to assess the relative bioavailability of racemic ketoprofen for both enantiomers between those routes of administration in growing pigs.

Methods

Eleven pigs received racemic ketoprofen at dose rates of 4 mg/kg PO and 3 mg/kg IM in a randomized, crossover design with a 6-day washout period. Enantiomers were separated on a chiral column and their concentrations were determined by liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated and relative bioavailability (F_rel) was determined for S and R –ketoprofen.

Results

S-ketoprofen was the predominant enantiomer in pig plasma after administration of the racemic mixture via both routes. The mean (± SD) maximum S-ketoprofen concentration in plasma (7.42 mg/L ± 2.35 in PO and 7.32 mg/L ± 0.75 in IM) was more than twice as high as that of R-ketoprofen (2.55 mg/L ± 0.99 in PO and 3.23 mg/L ± 0.70 in IM), and the terminal half-life was three times longer for S-ketoprofen (3.40 h ± 0.91 in PO and 2.89 h ± 0.85 in IM) than R-ketoprofen (1.1 h ± 0.90 in PO and 0.75 h ± 0.48 in IM). The mean (± SD) relative bioavailability (PO compared to IM) was 83 ± 20% and 63 ± 23% for S-ketoprofen and R-ketoprofen, respectively.

Conclusions

Although some minor differences were detected in the ketoprofen enantiomer concentrations in plasma after PO and IM administration, they are probably not relevant in clinical use. Thus, the pharmacological effects of racemic ketoprofen should be comparable after intramuscular and oral routes of administration in growing pigs.

Dose-response investigation of oral ketoprofen in pigs challenged with Escherichia coli endotoxin

In order to determine the effective dose, the effects of orally administered ketoprofen were evaluated in pigs following intravenous challenge with Escherichia coli endotoxin. One hour after the challenge, five groups of pigs were treated with either tap water or ketoprofen (0.5 mg/kg, 1 mg/kg, 2 mg/kg or 4 mg/kg). The body temperature was measured and a total clinical score was calculated after assessing the general behaviour, respiratory rate and locomotion of the pigs. Thromboxane B(2) and ketoprofen concentrations were analysed from blood samples. Ketoprofen treatment significantly reduced the rectal temperature and total clinical scores, and lowered blood thromboxane B(2) concentrations when compared with the control group. Ketoprofen plasma concentrations were lower than previously reported in healthy pigs after similar doses. The appropriate dose of orally administered ketoprofen in pigs in this model is 2 mg/kg, as the higher dose of 4 mg/kg failed to provide an additional benefit.

Chiral inversion of R(-) to S(+) ketoprofen in pigs

The S(+) enantiomer of ketoprofen is predominant in the plasma of pigs after administration of racemic ketoprofen, although the occurrence and extent of R(-)-to-S(+) inversion is uncertain. Plasma concentrations of both enantiomers were measured and percentages of S(+) ketoprofen were calculated at different time points after intravenous and oral dosing of pigs with 1.5mg/kg R(-) ketoprofen. S(+) ketoprofen was formed immediately after administration and concentrations exceeded R(-) concentrations after 1h. Absence of pre-systemic inversion was deduced from the lower S(+) percentages after oral administration. A rapid and increasing inversion, reaching a maximum of about 70%, occurred and appeared to be responsible for the predominance of S(+) ketoprofen in pig plasma after administration of the racemate.

Species comparison of oral bioavailability, first-pass metabolism and pharmacokinetics of acetaminophen

Species differences in oral bioavailability, first-pass metabolism and pharmacokinetics of biopharmaceutics classification system (BCS) class I compound acetaminophen were studied. The absolute bioavailability was 42.2%, 39.0%, 44.5%, 75.5% and 91.0% in chickens, turkeys, dogs, pigs and horses, respectively. After hydrolysis of metabolites by beta-glucuronidase/sulfatase, apparent bioavailability increased significantly in all species (turkeys: 72.4%, dogs: 100.5%, pigs: 102.2%), except horses (91.6%). Mean metabolic ratios of [acetaminophen glucuronide]/[acetaminophen] between 0 and 1h were significantly higher after oral dosing in turkeys, dogs and pigs, revealing the role of first-pass metabolism in incomplete bioavailability. Evidence of species differences in acetaminophen metabolism is provided by differences in plasma clearance, which was inversely proportional to bioavailability. In conclusion, differences in BA appeared to originate predominantly from differences in first-pass metabolism, demonstrating that the BCS high permeability classification of acetaminophen is consistent across the mammalian species studied. In turkeys, however, incomplete absorption additionally seemed to contribute to the low BA.