Two different salts of diclofenac, diclofenac sodium and diclofenac potassium, in tablet dosage form were tested for their bioavailability and disposition kinetics in a group of eighteen rabbits in normal and experimentally induced dehydrated conditions with a wash out period of 7 days between both stages of study. Biochemical and physiological parameters were also measured in both normal and dehydrated states. Diclofenac levels in plasma were determined using a validated reversed phase HPLC method. Primary kinetic parameters i.e. AUC(0-infinity), Cmax, Tmax and other disposition kinetics were obtained with non-compartmental procedure. Biochemical parameters i.e. packed cell volume, plasma glucose and total lipid concentration in dehydrated rabbits increased significantly. Plasma concentration of diclofenac sodium and diclofenac potassium decreased significantly in water deprived rabbits. In comparison, diclofenac potassium in normal and dehydrated state of the same group of rabbits showed a significantly increased plasma concentration when compared with diclofenac sodium.
Administration, Oral ; Animals ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; blood ; pharmacokinetics ; Area Under Curve ; Biological Availability ; Dehydration ; metabolism ; Diclofenac ; administration & dosage ; analogs & derivatives ; blood ; pharmacokinetics ; Rabbits ; Tablets

AIMTo investigate the in vitro recovery and influencing factors of ketoprofen in microdialysis probe, and study the pharmacokinetic of unbound ketoprofen in rat after iv administration.

METHODSThe recovery of ketoprofen was detected by a concentration difference method. After microdialysis probe was inserted into the jugular vein of male Wistar rats, the probe was infused with various concentrations perfusate. The in vivo recovery and the pharmacokinetics of unbound ketoprofen in rat were investigated. Dialysate samples were determined by HPLC.

RESULTSThe recovery detected by gain was as the same as that by loss; the recovery was independent of the drug concentration surrounding the probe. The in vitro recovery was 28.75% by concentration difference method and the in vivo recovery was (40.3 +/- 2.7) % by retrodialysis method. After i.v. administration of ketoprofen in rat, T 1/2, AUC and CL of unbound ketoprofen were (181 +/- 16) min, (112 +/- 27) microg x min x mL(-1) and (0.22 +/- 0.05) L x min(-1), respectively.

CONCLUSIONMicrodialysis sampling can be used for the pharmacokinetic study of unbound ketoprofen in rat.

Animals ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; pharmacokinetics ; Area Under Curve ; Chromatography, High Pressure Liquid ; Injections, Intravenous ; Ketoprofen ; administration & dosage ; pharmacokinetics ; Male ; Microdialysis ; methods ; Rats ; Rats, Wistar

The present research was aimed to develop a high performance liquid chromatography (HPLC) method to determine oxaprozin in plasma and to evaluate the bioavailability of two oxaprozin enteric coated tablets. A C18 column was used to separate the plasma after protein precipitation and the mobile phase was methanol-12. 5mmol/L ammonium acetate buffer solution (pH=3.0)(71:29). The calibration curve was linear in the concentration range of 0. 50-70. 56 microg . mL-1, and the intra and inter-day RSDs were less than 12. 33% and 10. 42% respectively. A single dose of 0. 4 g reference preparation or test preparation of oxaprozin enteric coated tablets was administered to 20 healthy volunteers according to a randomized crossover study. AUC0-->264h were (4 917. 44 +/- 629. 57) microg . h . mL-1 and (4 604. 30+/-737. 83) microg . h . mL-1, respectively; Cmax were (52. 34+/-7. 68) microg . mL-1 and (48. 66+/-4. 87) microg . mL-1, respectively; Tmax were (18. 70+/-2.27) h and (19. 30+/-1. 63) h, respectively; The relative bioavailability of test preparation was 94.0% +/- 13. 7%. The method is simple, rapid and selective for oxaprozin determination. There is no significant difference in the main pharmacokinetic parameters between the test formulation and reference formulation and the two formulations are in bioequivalence.
Anti-Inflammatory Agents, Non-Steroidal ; blood ; pharmacokinetics ; Biological Availability ; Chromatography, High Pressure Liquid ; Cross-Over Studies ; Humans ; Propionates ; administration & dosage ; blood ; pharmacokinetics ; Tablets, Enteric-Coated

To study the tissue distribution and excretion of indomethacin 5-fluorouracil-1-ylmethyl ester (IFM) metabolite 5-fluorouracil in rats, an accurate and specific high performance liquid chromatography method for quantifying IFM in rat plasma and tissues was developed. Biological samples were prepared by liquid-liquid extraction and separated on a Diamonsil C18 column (250 mm x 4.6 mm ID, 5 microm). The mobile phase for tissue samples, plasma samples and feces samples were composed of methanol-water-36% acetic acid (3:96.9:0.1, v/v) and the mobile phase for urine samples was a mixture of methanol-water-36% acetic acid (10:89.9:0.1, v/v). The eluate was monitored by UV absorbance at 260 nm. After a single ig dose of 100 mg x kg(-1) IFM in rats, 5-Fu was mainly distributed in stomach, small intestine, and liver. The concentrations of 5-fluorouracil in other tissues and plasma were low. The excretion of 5-Fu in urine and feces amounted to 0.0065% and 0.063% of the dose, respectively. The method is shown to be accurate and specific, and suitable for preclinical pharmacokinetic studies of IFM.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; metabolism ; pharmacokinetics ; urine ; Antimetabolites, Antineoplastic ; pharmacokinetics ; urine ; Feces ; chemistry ; Female ; Fluorouracil ; pharmacokinetics ; urine ; Indomethacin ; metabolism ; pharmacokinetics ; urine ; Male ; Prodrugs ; pharmacokinetics ; Random Allocation ; Rats ; Rats, Wistar ; Sensitivity and Specificity ; Tissue Distribution

Inhibition of cyclooxygenase(COX), and thus prevention of the formation of prostaglandins, provided a unifying explanation of the therapeutic and toxic actions of nonsteroidal anti-inflammatory drugs(NSAIDs). Recently, the discovery of the two isoforms of COX was made by molecular biologists studying neoplastic transformation in chick embryo cells. The constitutive enzyme, COX-1, is obviously responsible for the production of prostaglandins involved in housekeeping functions such as maintenance of integrity of the gastric mucosa, renal blood flow and platelet aggregation. The inducible form of COX(COX-2) is responsible for the formation of prostaglandins that pathologic effects of inflammation, pain and fever. Clearly, all the experimental and clinical data support the hypothesis that the beneficial effects of NSAIDs are due to inhibition of the COX-2 enzyme, whereas the gastrotoxicity is due to inhibition of COX-1. The COX-2/COX-1 ratios of the NSAIDs in common use have been measured and compared with epidemiological data on their side effects. there is little evidence to suggest that one NSAID is clearly more efficacious than another and substantial individual variability is present with respect to the pharmacology and pharmacokinetics of these drugs, it is essential to adjust the dosage and choose specific drug to the patient`s response.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; Chick Embryo ; Fever ; Gastric Mucosa ; Housekeeping ; Inflammation ; Pharmacokinetics ; Pharmacology ; Platelet Aggregation ; Prostaglandins ; Protein Isoforms ; Renal Circulation ; Toxic Actions

A comparative pharmacokinetic study of diclofenac (1 mg/kg, i.v.) when given alone or in combination with enrofloxacin (4 mg/kg, i.v.) in five buffalo calves was carried out by using HPLC. The study revealed that the plasma concentrations of diclofenac were significantly lower (p<0.05) in combined administration of diclofenac with enrofloxacin (0.042 to 3 h), whereas significantly higher (p<0.05) levels of plasma drug concentrations were observed in later period (8 to 24 h). In urine, significantly lower (p<0.05) drug concentrations of diclofenac were observed from 0.167 to 1.5 h, whereas significantly higher (p<0.01) urine drug concentrations were observed in later period (4 to 48 h) when diclofenac was given in combination with enrofloxacin as compared to when diclofenac was given alone. Various kinetic parameters like A, Cpo and beta were significantly lower (p<0.05) whereas t1/2 beta, AUMC, MRT and various volume of distribution (VdC, VdB, Vdarea and VdSS) were significantly higher in combined administration of diclofenac with enrofloxacin as compared to when diclofenac was given alone (p<0.05).
Animals ; Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics ; Area Under Curve ; Buffaloes ; Diclofenac/blood/*pharmacokinetics/urine ; Drug Interactions ; Female ; Fluoroquinolones/blood/*pharmacokinetics/urine ; Milk/chemistry ; Quinolones/blood/*pharmacokinetics/urine ; Tissue Distribution

This study involves mathematical simulation model such as in vitro-in vivo correlation (IVIVC) development for various extended release formulations of nimesulide loaded hydroxypropylmethylcellulose (HPMC) microparticles (M1, M2 and M3 containing 1, 2, and 3 g HPMC, respectively and 1 g drug in each) having variable release characteristics. In vitro dissolution data of these formulations were correlated to their relevant in vivo absorption profiles followed by predictability worth analysis of these Level A IVIVC. Nimaran was used as control formulation to validate developed formulations and their respective models. The regression coefficients of IVIVC plots for M1, M2, M3 and Nimaran were 0.834 9, 0.831 2, 0.927 2 and 0.898 1, respectively. The internal prediction error for all formulations was within limits, i.e., < 10%. A good IVIVC was found for controlled release nimesulide loaded HPMC floating M3 microparticles. In other words, this mathematical simulation model is best fit for biowaiver studies which involves study parameters as those adopted for M3 because the value of its IVIVC regression coefficient is the closest to 1 as compared to M1 and M2.
Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; pharmacokinetics ; Cross-Over Studies ; Cyclooxygenase 2 Inhibitors ; administration & dosage ; pharmacokinetics ; Delayed-Action Preparations ; Humans ; Hypromellose Derivatives ; Methylcellulose ; analogs & derivatives ; Microspheres ; Models, Chemical ; Sulfonamides ; administration & dosage ; pharmacokinetics

The pharmacokinetics of ibuprofen enantiomers were studied in rats after intravenous and oral administration of ibuprofen arginate by means of a chiral HPLC method. The pharmacokinetics of ibuprofen was stereoselective after intravenous and oral administration of ibuprofen arginate. The pharmacokinetic stereoselectivity was higher after oral administration than that after intravenous administration. The systematic (R)-(-)-to-(S)-(+) inversion might be more important than the presystematic one in the stereoselective pharmacokinetics after oral administration. Oral administration of ibuprofen arginate resulted in a very rapid absorption of (S)-(+)-ibuprofen (eutomer), and the absolute bioavailabilities of (S)-(+)-ibuprofen and (R)-(-)-ibuprofen were about 100% and 80%, respectively. Based on the systemic exposure of (S)-(+)-ibuprofen, it could be concluded that the pharmacological actions might be similar when ibuprofen arginate was given orally and intravenously, except some differences in the onset of action.
Absorption ; Administration, Intravenous ; Administration, Oral ; Animals ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; pharmacokinetics ; Area Under Curve ; Arginine ; administration & dosage ; pharmacokinetics ; Biological Availability ; Chromatography, High Pressure Liquid ; Drug Combinations ; Ibuprofen ; administration & dosage ; pharmacokinetics ; Male ; Rats ; Rats, Sprague-Dawley ; Stereoisomerism

AIMTo reconstruct of a tissue engineering skin in vitro for the study of the use of drug percutaneous penetration and metabolism.

METHODSDermal fibroblasts were embedded in collagen type I. HaCaT cells were seeded on the top of the gel. The skin was generated through air-liquid interface culture. Effects of various culture media on tissues morphology were investigated. Sections of the cultured skin were stained with hematoxylin and eosin and examined under microscope. Permeation and metabolism of ketoprofen and its isopropyl ester through the cultured skin were investigated.

RESULTSHaCaT cells initially developed a multilayer epithelium at the air-liquid interface, but it showed a parakeratotic stratum corneum. Vitamin C enhanced cell proliferation obviously. Vitamin D3 promoted cell differentiation. And estradiol showed little effect on the tissue engineering skin. Ketoprofen isopropyl ester was hydrolyzed into ketoprofen when penetrated through the cultured skin, which resembled in the skin cell homogenates metabolism.

CONCLUSIONCultured at the air-liquid interface, HaCaT cells developed a parakeratotic mutilayer epithelium. Enzyme activity was reserved. This cultured skin could serve as an appropriate model for drug percutaneous metabolism and skin irritation.

Administration, Cutaneous ; Anti-Inflammatory Agents, Non-Steroidal ; pharmacokinetics ; Esters ; administration & dosage ; chemistry ; pharmacokinetics ; HeLa Cells ; cytology ; Humans ; Ketoprofen ; administration & dosage ; chemistry ; pharmacokinetics ; Skin Absorption ; Skin, Artificial ; Tissue Engineering ; methods

AIMTo establish an in situ perfused pig ear model for percutaneous absorption.

METHODSThe in situ perfused pig ear model for percutaneous absorption consisted of artificial gas, sample chamber, constant flow pump, constant temperature system, polytetrafluorethylene connective tube, porcine ear vein, porcine ear skin and special laminar flow apparatus. The perfused system viability was assessed by glucose utilization and lactate production. Ketoprofen isopropyl ester and methyl salicylate was used for validating this model. The concentrations of perfused sample were measured by HPLC.

RESULTSGlucose utilization and lactate production showed that this model was viable till 7 h. Ketoprofen isopropyl ester was completely metabolized to ketoprofen in situ in perfused pig ear model. The steady cumulative amount (Q) of ketoprofen from permeation and metabolism was linear with time (t), the equation of ketoprofen formation was Q = -0.024 + 0.120t, the rate of ketoprofen formation was 0.120 microgram.cm-2.h-1. Methyl salicylate was partially metabolized to salicylic acid. The steady cumulative amount (Q) of methyl salicylate from permeation was linear with time (t), the permeation equation of methyl salicylate was Q = -3.809 + 6.129t, the permeation rate of metyl salicylate was 6.129 micrograms.cm-2.h-1. The steady cumulative amount (Q) of salicylic acid from metabolism was also linear with time (t), the formation equation of salicylic acid was Q = -1.785 + 0.879t, the formation rate of salicylic acid was 0.879 microgram.cm-2.h-1.

CONCLUSIONThe in situ pig ear vein perfused model is a novel easy-handing and cost-efficient technique for percutaneous absorption and skin metabolism.

Administration, Cutaneous ; Animals ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; metabolism ; pharmacokinetics ; Ear, External ; blood supply ; Ketoprofen ; administration & dosage ; metabolism ; pharmacokinetics ; Male ; Models, Animal ; Perfusion ; Salicylates ; administration & dosage ; pharmacokinetics ; Salicylic Acid ; metabolism ; Skin ; metabolism ; Skin Absorption ; Swine ; Veins