Pharmacokinetics of meloxicam, carprofen, and tolfenamic acid after intramuscular and oral administration in Japanese quails (Coturnix coturnix japonica)

Pharmacokinetics of meloxicam following intravenous administration at different doses in sheep

The aim of this study is to determine the pharmacokinetic change after intravenous administration of meloxicam at doses of 0.5, 1 and 2 mg/kg to sheep. The study was carried out on six Akkaraman sheep. Meloxicam was administered intravenously to each sheep at 0.5, 1, and 2 mg/kg doses in a longitudinal pharmacokinetic design with a 15-day washout period. Plasma concentrations of meloxicam were determined using the high performance liquid chromatography-ultraviolet, and pharmacokinetic parameters were evaluated by non-compartmental analysis. Meloxicam was detected up to 48 h in the 0.5 mg/kg dose and up to 96 h in the 1 and 2 mg/kg doses. As the dose increased from 0.5 to 2 mg/kg, terminal elimination half-life, and dose normalized area under the concentration versus time curve increased and total clearance decreased. Compared to the 1 mg/kg dose, it was determined that Vdss decreased and C0.083h increased in the 2 mg/kg dose. Meloxicam provided the therapeutic concentration of >0.39 μg/mL reported in other species for 12, 48 and 96 h at 0.5, 1 and 2 mg/kg doses, respectively. These results show that meloxicam exhibits non-linear pharmacokinetics and will achieve unpredictable plasma concentrations when administered IV for a rapid effect at dose of ≥1 mg/kg in sheep.

Analysis of Tolfenamic Acid using a Simple, Rapid, and Stability-indicating Validated HPLC Method

BACKGROUND

Tolfenamic acid (TA) belongs to the fenamates class of nonsteroidal anti-inflammatory drugs. Insufficient information is available regarding the availability of a reliable and validated stability-indicating method for the assay of TA.

OBJECTIVE

A relatively simple, rapid, accurate, precise, economical, robust, and stabilityindicating RP-HPLC method has been developed to determine TA in pure and tablet dosage forms.

METHODS

The method was validated according to the ICH guideline, and parameters like linearity, range, selectivity, accuracy, precision, robustness, specificity, and solution stability were determined. TLC and FTIR spectrometry were used to ascertain the purity of TA. The specificity was determined with known impurities and after performing forced degradation, while the robustness was established by Plackett-Burman's experimental design. The mobile phase used for the analysis was acetonitrile and water (90:10, v/v) at pH 2.5. The detection of the active drug was made at 280 nm using a C18 column (tR = 4.3 min.). The method's applicability was also checked for the yellow polymorphic form of TA.

RESULTS

The results indicated that the method is highly accurate (99.39-100.80%), precise (<1.5% RSD), robust (<2% RSD), and statistically comparable to the British Pharmacopoeia method with better sensitivity and specificity.

CONCLUSION

It was observed that the stress degradation studies do not affect the method's accuracy and specificity. Hence the proposed method can be used to assay TA and its tablet dosage form.

Pharmacokinetics and bioavailability of meloxicam in Pekin ducks following intravenous, intramuscular and oral administration

OBJECTIVE

To determine the pharmacokinetics and bioavailability of meloxicam following intravenous (IV), intramuscular (IM), and oral administrations at a dose of 1.0 mg kg-1 in Pekin ducks.

STUDY DESIGN

Randomized experimental trial.

ANIMALS

A total of 18 clinically healthy male Pekin ducks.

METHODS

Pekin ducks were randomly assigned to three groups of six ducks: IV, IM and oral. Meloxicam (1.0 mg kg-1) was administered to each Pekin duck. A non-compartmental analysis was used to evaluate pharmacokinetic parameters.

RESULTS

No local or systemic adverse effects were observed in any bird. Meloxicam was detected in the plasma up to 120 hours following IV, IM or oral administration. The elimination half-life of the IV route was slightly shorter than that of the IM and oral routes (p < 0.05). Following IV administration, volume of distribution at steady state and total clearance were 133.17 mL kg-1 and 6.68 mL kg-1 hour-1, respectively. The mean absorption time was 2.29 hours for IM and 1.13 hours for oral route. There were significant differences between IM and oral administration for the peak plasma concentration (Cmax), time to reach Cmax and bioavailability (p < 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

Meloxicam showed long elimination half-life and high bioavailability following IM and oral administration. Meloxicam in Pekin ducks provided the effective therapeutic concentration indicated in other species for up to 48 hours. However, there is a need to determine the clinical efficacy of meloxicam in Pekin ducks.

Effect of Xylazine on Pharmacokinetics and Physiological Efficacy of Intravenous Carprofen in Castrated Goats Kids

Carprofen can be used in the castration process of male goats due to its low side effects, long elimination half-life, and long-term effect. However, no studies were found on the pharmacokinetics and physiological efficacy of carprofen when employed for castration in male goats. The aim of this study was to determine the effect of xylazine (0.05 mg/kg, intramuscular) on the pharmacokinetics and physiological efficacy following intravenous administration of carprofen (4 mg/kg, intravenous) in male goat kids castrated using the burdizzo method. Thirty male Kilis goat kids (5-6 months and 18-30 kg of body weight) were randomly assigned to five groups (n = 6) as follows: healthy control (HC), castration control (CAST), castration+carprofen (CAST+CRP), castration+xylazine (CAST+XYL), and castration+xylazine+carprofen (CAST+XYL+CRP). Plasma concentrations of carprofen were analyzed via a non-compartmental method. Physiological parameters including serum cortisol, scrotal temperature, rectal temperature, and scrotal circumference were determined. Xylazine caused a decrease in the volume of distribution and clearance and an increase in the area under the curve of carprofen in CAST+XYL+CRP group (p < 0.05). The mean cortisol concentrations in CAST+CRP and CAST+XYL remained lower compared to CAST (p < 0.05). The mean cortisol concentrations in CAST+XYL+CRP were lower than in CAST+CRP and CAST+XYL (p < 0.05). In addition, the effect of carprofen administration alone on reducing the initial cortisol response to castration was observed from 6 to 48 h, while in combination with xylazine, it was observed immediately up to 48 h. No treatment differences were observed in rectal temperature, scrotal temperature, and scrotal circumference (p > 0.05). Xylazine caused an increase in plasma concentration and a decrease in clearance of carprofen after co-administration. However, when the effect of the combined administration of carprofen with xylazine on cortisol is evaluated, their combined use in castration process may be beneficial.

Treatment of Pain in Birds

This article provides an overview of the current understanding of evidence-based clinical analgesic use in birds. The field of avian analgesia has dramatically expanded during the last 20 years, affording more options for alleviating both acute and chronic pain. These options include opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and/or other drugs like gabapentin, amantadine, and cannabinoids, acting at different points in the nociceptive system thereby helping to provide greater pain relief while reducing the risk of adverse effects when combined.

Pharmacokinetics and bioavailability of carprofen in sheep

The aim of this study was to determine the pharmacokinetics and bioavailability of carprofen in sheep following single intravenous (IV), intramuscular (IM), subcutaneous (SC), and oral (PO) administrations of a parenteral formulation at a dose of 4 mg/kg. A total of eight sheep were used for the investigation. The study comprised four periods, according to a crossover design with a 21-day washout period between treatments. Plasma concentrations of carprofen were measured using HPLC-UV. Pharmacokinetic parameters were estimated by non-compartmental model analysis. Following IV administration, t_1/2ʎz , Cl_T , and V_dss were 43.36 h, 1.98 ml/h/kg, and 121.36 ml/kg, respectively. The C_max(obs) was 26.57 mg/ml for the IM, 23.76 mg/ml for the SC, and 15.90 mg/ml for the PO. The bioavailability following IM, SC, and PO administrations was 75.47%, 82.00%, and 62.51%, respectively. Plasma creatine kinase activity increased significantly at 3, 6, and 12 h following IM administration of carprofen. Despite differences in plasma concentrations and bioavailability among administration routes, carprofen at 4 mg/kg dose may provide the plasma concentration (>1.5 μg/ml) needed for analgesic effect during 144 h in all routes. However, because of the slow absorption rate after SC and PO routes, the IV route may be preferred primarily for the rapid onset in the analgesic and anti-inflammatory effect of carprofen in sheep. Despite the favorable kinetics, the muscle damage caused by IM injection limits use of carprofen via IM route.

Pharmacokinetics of carprofen following single and repeated intravenous administrations of different doses in sheep

The aim of this study was to determine the pharmacokinetics of carprofen following single and repeated intravenous (IV) administrations at 1.4 and 4 mg/kg doses in sheep. The study was carried out on twelve sheep in two experiments as single- and multiple-dose pharmacokinetics. In experiment 1, carprofen was administered via IV at single doses of 1.4 (n = 6) and 4 mg/kg (n = 6) in a randomized parallel design. In experiment 2, the same dose groups in experiment 1 following the 21-day washout period received intravenously carprofen every 24 h for 5 days. Plasma concentrations were measured using high-performance liquid chromatography-UV and analyzed by a two-compartment open model. After the single administration of 1.4 mg/kg dose, the t_1/2α , t_1/2el , MRT, Cl_T , V_dss , and AUC were 0.62 h, 27.57 h, 38.78 h, 2.72 ml/h/kg, 105.26 ml/kg, and 515.12 h*μg/ml, respectively. Carprofen at a single dose of 4 mg/kg showed prolonged t_1/2el and MRT, and increased V_dss . On day 5 after the repeated administration of the 1.4 mg/kg dose, the t_1/2α , t_1/2el , MRT, Cl_T , V_dss , and AUC were 1.12 h, 57.48 h, 82.18 h, 0.55 ml/h/kg, 45.43 ml/kg, and 2532 h*μg/ml, respectively. Carprofen at a repeated dose of 4 mg/kg showed increased Cl_T and V_dss and decreased AUC/dose. Although the long t_1/2ʎz in single and multiple IV dose studies suggest the possibility of its effective use, the IV route may not be practical in sheep. Therefore, oral and subcutaneous routes of carprofen in sheep would be more valuable in clinical settings.

Pharmacokinetics and bioavailability of meloxicam in rainbow trout (Oncorhynchus mykiss) broodstock following intravascular, intramuscular, and oral administrations

The pharmacokinetics and bioavailability of meloxicam were investigated after single intravascular (IV), intramuscular (IM), and oral dose of 1 mg/kg in rainbow trout broodstock at 11 ± 1.2°C. A total of 36 healthy rainbow trout (Oncorhynchus mykiss) broodstock weighing 1.40 ± 0.26 kg was used for the investigation. Plasma concentrations of meloxicam were measured with high-performance liquid chromatography-ultraviolet detection, and pharmacokinetic parameters were calculated by non-compartmental analysis. The elimination half-life for IV, IM, and oral routes was 3.63, 4.55, and 2.95 h, respectively. The IV route for meloxicam showed the total clearance of 0.05 L/h/kg and volume of distribution at a steady state of 0.20 L/kg. The peak plasma concentration was 2.97 μg/ml for the IM route and 0.84 μg/ml for the oral route. The bioavailability was 78.45% for the IM route and 21.48% for the oral route. Meloxicam following IM and oral administration displayed short t_1/2ʎz . The short t_1/2ʎz could be an advantage for the short-term use in acute conditions. The IM route with the good bioavailability can be preferred for the treatment of various conditions. However, developing new oral formulations with the good bioavailability for meloxicam is necessary to minimize stress and trauma through minimal handling in rainbow trout broodstock.

Pharmacokinetics and Bioavailability of Carprofen in Rainbow Trout (Oncorhynchus mykiss) Broodstock

The aim of this study was to determine the pharmacokinetics of carprofen following intravenous (IV), intramuscular (IM) and oral routes to rainbow trout (Oncorhynchus mykiss) broodstock at temperatures of 10 ± 1.5 °C. In this study, thirty-six healthy rainbow trout broodstock (body weight, 1.45 ± 0.30 kg) were used. The plasma concentrations of carprofen were determined using high-performance liquid chromatography and pharmacokinetic parameters were calculated using non-compartmental analysis. Carprofen was measured up to 192 h for IV route and 240 h for IM, and oral routes in plasma. The elimination half-life (t1/2λz) was 30.66, 46.11, and 41.08 h for IV, IM and oral routes, respectively. Carprofen for the IV route showed the total clearance of 0.02 L/h/kg and volume of distribution at steady state of 0.60 L/kg. For IM and oral routes, the peak plasma concentration (Cmax) was 3.96 and 2.52 μg/mL with the time to reach Cmax of 2 and 4 h, respectively. The bioavailability was 121.89% for IM route and 78.66% for oral route. The favorable pharmacokinetic properties such as the good bioavailability and long t1/2λz for IM and oral route of carprofen suggest the possibility of its effective use for the treatment of various conditions in broodstock.