Lactant de 6 setmanes amb tumefacció preauricular I febre d'aparició sobtada / No disponible

No disponible

Absorbable antibiotic beads as an adjuvant therapy in treating ventricular assist devices driveline infection: A case report.

BACKGROUND: Ventricular assist devices driveline infections are common, recalcitrant, and carry high morbidity and mortality. Herein, we reported a patient with driveline infection that was successfully treated with a combination of systemic antibiotics, surgical debridement, and instillation of absorbable antibiotic beads to the wound bed. METHODS AND RESULTS: A 39-year-old man with nonischemic cardiomyopathy underwent insertion of a continuous flow left ventricular assist device. Four years postoperatively, the patient presented with clinical, laboratory, and radiologic signs of driveline tract infection. He underwent extensive surgical debridement, installation of absorbable antibiotic beads that consisted of calcium sulfate, vancomycin, and tobramycin, into the wound bed, and systemic antibiotics. The patient was free of infection 9 month postoperatively. CONCLUSION: Absorbable calcium sulfate antibiotic beads may serve as a beneficial adjunct to surgical debridement and systemic antibiotics for the treatment of ventricular assist device driveline infection, and merit further investigation.

Transient Fanconi Syndrome After Treatment with Firocoxib, Cefadroxil, Tramadol, and Famotidine in a Maltese.

Fanconi syndrome is a renal proximal tubulopathy characterized by excessive urinary loss of glucose, amino acids, several electrolytes, and bicarbonate. Here, we report the case of transient Fanconi syndrome in a dog following administration of firocoxib, cefadroxil, tramadol, and famotidine. A 10 mo old Maltese was presented with lethargy, anorexia, vomiting, and weight loss. Transient Fanconi syndrome without azotemia was associated with firocoxib, cefadroxil, tramadol, and famotidine treatment. The dog received supportive care including IV fluids, gastroprotectants, and oral nutritional supplements. Two months after initial diagnosis and treatment, the dog showed complete resolution of glucosuria and aminoaciduria. The unique features of Fanconi syndrome in this case emphasize the potential renal tubular toxicity of this widely used multiple-drug combination.

In Silico Prediction of the Absorption and Disposition of Cefadroxil in Humans using an Intestinal Permeability Method Scaled from Humanized PepT1 Mice.

It is difficult to predict the pharmacokinetics and plasma concentration-time profiles of new chemical entities in humans based on animal data. Some pharmacokinetic parameters, such as clearance and volume of distribution, can be scaled allometrically from rodents, mammals, and nonhuman primates with good success. However, it is far more challenging to predict the oral pharmacokinetics of experimental drug candidates. In the present study, we used in situ estimates of intestinal permeability, obtained in silico and from rat, wild-type (WT), and humanized PepT1 (huPepT1) mice, to predict the systemic exposure of cefadroxil, an orally administered model compound, under a variety of conditions. Using the GastroPlus simulation software program (Simulations Plus, Lancaster, CA), we found that the C max and area under the plasma concentration-time curve from time zero to the last measurable concentration of cefadroxil were better predicted using intestinal permeability estimates (both segmental and jejunal) from huPepT1 than from WT mice, and that intestinal permeabilities based on in silico and rat estimates gave worse predictions. We also observed that accurate predictions were possible for cefadroxil during oral dose escalation (i.e., 5, 15, and 30 mg/kg cefadroxil), a drug-drug interaction study (i.e., 5 mg/kg oral cefadroxil plus 45 mg/kg oral cephalexin), and an oral multiple dose study [i.e., 500 mg (6.7 mg/kg) cefadroxil every 6 hours]. Finally, the greatest amount of cefadroxil was absorbed in duodenal and jejunal segments of the small intestine after a 5 mg/kg oral dose. Thus, by combining a humanized mouse model and in silico software, the present study offers a novel strategy for better translating preclinical pharmacokinetic data to oral drug exposure during first-in-human studies.

Extended Oral Antibiotic Prophylaxis in High-Risk Patients Substantially Reduces Primary Total Hip and Knee Arthroplasty 90-Day Infection Rate.

BACKGROUND: Total joint arthroplasty (TJA) episodic payment models shift risk and cost of periprosthetic joint infection (PJI) to surgeons and hospitals, causing some to avoid treating high-risk patients. Furthermore, there are little data to support optimization of host factors preoperatively to decrease PJI, and recent literature supports using extended antibiotic prophylaxis following reimplantation TJA. The purpose of this study was to evaluate whether extended oral antibiotic prophylaxis minimized PJI after primary TJA in high-risk patients. METHODS: A retrospective cohort study was performed of 2,181 primary total knee arthroplasties (TKAs) and primary total hip arthroplasties (THAs) carried out from 2011 through 2016 at a suburban academic hospital with modern perioperative and infection-prevention protocols. Beginning in January 2015, extended oral antibiotic prophylaxis for 7 days after discharge was implemented for patients at high risk for PJI. The percentages of patients diagnosed with PJI within 90 days were identified and compared between groups that did and did not receive extended oral antibiotic prophylaxis, with p ≤ 0.05 indicating significance. RESULTS: The 90-day infection rates were 1.0% and 2.2% after the TKAs and THAs, respectively. High-risk patients without extended antibiotic prophylaxis were 4.9 (p = 0.009) and 4.0 (p = 0.037) times more likely to develop PJI after TKA and THA, respectively, than high-risk patients with extended antibiotic prophylaxis. CONCLUSIONS: Extended postoperative antibiotic prophylaxis led to a statistically significant and clinically meaningful reduction in the 90-day infection rate of selected patients at high risk for infection. We encourage further study and deliberation prior to adoption of a protocol involving extended oral antibiotic prophylaxis after high-risk TJA, with the benefits weighed appropriately against potential adverse consequences such as increasing the development of antimicrobial resistance. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A potential antibacterial wound dressing of cefadroxil chitosan nanoparticles in situ gel: Fabrication, in vitro optimization and in vivo evaluation.

Wound healing following skin injury is a natural phenomenon that usually lacks quality, rapidity, and aesthetics. Thus, the purpose of this study was to fabricate a new easily applied in situ gel of cefadroxil (CDX) loaded chitosan nanoparticles (CDX-CSNPs) that could promote wound healing, capable of inhibiting the possible accompanying bacterial infection. The nanoparticles were prepared by double emulsion technique and the influence of formulation parameters on drug entrapment efficiency (EE%), particle size (PS), polydispersity index (PDI) and zeta potential (ZP) were investigated using a full factorial design. The results show that the optimized CDX-CSNP1 composed of low molecular weight chitosan (0.2%w/v) was spherical with EE%, PS, PDI and ZP of 84.25 ±â€¯0.02, 408.30 ±â€¯53.17 nm, 0.458 ±â€¯0.048 and 22.80 ±â€¯0.57 mV, respectively. DSC and XRD studies confirmed the amorphous nature of the drug. After ensuring the safety and non toxicity of CDX-CSNP1 in situ gel through cytotoxic study, the antibacterial activity was evaluated using a rat skin infection model against Staphylococcus aureus. Compared to the rats treated with free CDX, the CDX-CSNP1 treated group revealed a remarkable accelerated wound healing process and bacterial clearance which was further confirmed by the histopathological examination of skin biopsies.

Effect of Different Sampling Schedules on Results of Bioavailability and Bioequivalence Studies: Evaluation by Means of Monte Carlo Simulations.

Bioavailability and bioequivalence study is one of the most frequently performed investigations in clinical trials. Bioequivalence testing is based on the assumption that 2 drug products will be therapeutically equivalent when they are equivalent in the rate and extent to which the active drug ingredient or therapeutic moiety is absorbed and becomes available at the site of drug action. In recent years there has been a significant growth in published papers that use in silico studies based on mathematical simulations to analyze pharmacokinetic and pharmacodynamic properties of drugs, including bioavailability and bioequivalence aspects. The goal of this study is to evaluate the usefulness of in silico studies as a tool in the planning of bioequivalence, bioavailability and other pharmacokinetic assays, e.g., to determine an appropriate sampling schedule. Monte Carlo simulations were used to define adequate blood sampling schedules for a bioequivalence assay comparing 2 different formulations of cefadroxil oral suspensions. In silico bioequivalence studies comparing different formulation of cefadroxil oral suspensions using various sampling schedules were performed using models. An in vivo study was conducted to confirm in silico results. The results of in silico and in vivo bioequivalence studies demonstrated that schedules with fewer sampling times are as efficient as schedules with larger numbers of sampling times in the assessment of bioequivalence, but only if Tmax is included as a sampling time. It was also concluded that in silico studies are useful tools in the planning of bioequivalence, bioavailability and other pharmacokinetic in vivo assays.

Comparative bioavailability and pharmacokinetic study of Cefadroxil capsules in male healthy volunteers of Pakistan.

The current study was aimed to judge bioequivalence between two formulations of cefadroxil capsules as guided by FDA guidelines. Another objective was to conduct pharmacokinetic evaluation in Pakistani population. A single-dose, randomized, cross-over pharmacokinetic study was conducted during the month of May'2013 to August'2013. Washout period was one week. Fourteen healthy male adult volunteers were enrolled in the study, however twelve completed the study. Cefadroxil plasma concentration was analyzed by using validated HPLC method. Protein precipitation was achieved by the addition of 6% tri chloro acetic acid in 1:1 ratio and detection was done at 260 nm. Retention time was 7.792 min and correlation coefficient (R2) was 0.9953 showing linearity of the method. Blood sampling was carried out at different time intervals after administration of either test (TEST 500 mg) or reference (REF® 500 mg) formulation. Pharmacokinetic parameters (AUC0→ ∞, AUC0→ t, Cmax, Tmax, t1/2 and kel) were calculated using Kinetica® PK/PD software. The geometric mean ratios and 90% confidence interval (CI) of these pharmacokinetic parameters for cefadroxil (test and reference) formulations were 0.986 (90.83-106.98%) for AUC0→ t; 0.967 (89.13-104.92%) for AUC0→ ∞ and 0.999 (91.06-109.69%) for Cmax. The differences between Tmax of both formulations were not found to be statistically significant (p-value was more than 0.05). The 90% CI of the test/reference AUC and Cmax ratio of cefadroxil were within the FDA recommended range for bioequivalence. Maximum plasma concentration Cmax was 12.5 µg/ml for test and 12.47 µg/ml for reference formulations. Average time to reach Cmax for test and reference formulation was 1.54 and 1.5 hrs. The two formulations of cefadroxil studied during the above study were verified bioequivalent. Maximum plasma concentration of cefadroxil was lower than those mentioned in some previous studies, while Tmax and half-life were near to values reported in literature.

Species differences in the pharmacokinetics of cefadroxil as determined in wildtype and humanized PepT1 mice.

PepT1 (SLC15A1) is a high-capacity low-affinity transporter that is important in the absorption of digested di/tripeptides from dietary protein in the small intestine. PepT1 is also crucial for the intestinal uptake and absorption of therapeutic agents such as the ß-lactam aminocephalosporins and antiviral prodrugs. Species differences, however, have been observed in PepT1-mediated intestinal absorption and pharmacokinetics, thereby, making it more difficult to predict systemic drug exposure. In the present study, we evaluated the in situ intestinal permeability of the PepT1 substrate cefadroxil in wildtype and humanized PepT1 (huPepT1) mice, and the in vivo absorption and disposition of drug after escalating oral doses. The in situ perfusions indicated that cefadroxil had a twofold higher affinity (i.e., twofold lower Km) for jejunal PepT1 in huPepT1 mice, lower but substantial permeability in all regions of the small intestine, and low but measureable permeability in the colon as compared to wildtype animals. The in vivo experiments indicated almost superimposable pharmacokinetic profiles between the two genotypes after intravenous bolus dosing of cefadroxil. In contrast, after oral dose escalation, the systemic exposure of cefadroxil was reduced in huPepT1 mice as compared to wildtype animals. Moreover, the AUC and Cmax versus dose relationships were nonlinear for huPepT1 but not wildtype mice, and similar to that observed from human subjects. In conclusion, our findings indicate that huPepT1 mice may provide a valuable tool in the drug discovery process by better predicting the oral pharmacokinetic profiles of PepT1 substrates in humans.

Population pharmacokinetic modeling of cefadroxil renal transport in wild-type and Pept2 knockout mice.

1. Cefadroxil is a broad-spectrum ß-lactam antibiotic that is widely used in the treatment of various infectious diseases. Currently, poor understanding of the drug's pharmacokinetic profiles and disposition mechanism(s) prevents determining optimal dosage regimens and achieving ideal antibacterial responses in patients. In the present retrospective study, we developed a population pharmacokinetic model of cefadroxil in wild-type and Pept2 knockout mice using the nonlinear mixed effect modeling (NONMEM) approach. 2. Cefadroxil pharmacokinetics were best described by a two-compartment model, with both saturable and nonsaturable elimination processes to/from the central compartment. Through this modeling approach, pharmacokinetic parameters in wild-type and Pept2 knockout mice were well estimated, respectively, as follows: volume of central compartment V1 (3.43 versus 4.23 mL), volume of peripheral compartment V2 (5.98 versus 8.61 mL), intercompartment clearance Q (0.599 versus 0.586 mL/min) and linear elimination rate constant K10 (0.111 versus 0.070 min(-1)). Moreover, the secretion kinetics (i.e. V(m1) = 17.6 nmoL/min and K(m1) = 37.1 µM) and reabsorption kinetics (i.e. V(m2) = 15.0 nmoL/min and K(m2) = 27.1 µM) of cefadroxil were quantified in kidney, for the first time, under in vivo conditions. 3. Our model provides a unique tool to quantitatively predict the dose-dependent nonlinear disposition of cefadroxil, as well as the potential for transporter-mediated drug interactions.

Effects of 1α,25-dihydroxyvitamin D3 , the natural vitamin D receptor ligand, on the pharmacokinetics of cefdinir and cefadroxil, organic anion transporter substrates, in rat.

Evidence in the literature suggests that 1α,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ], the vitamin D receptor ligand, down-regulated the expression of the rat renal organic anion (renal organic anion transporter, rOAT) and oligopeptide (rPEPT) transporters, but increased intestinal rPEPT1 expression. We investigated, in rats, the intravenous and oral pharmacokinetics of 2 mg/kg cefdinir and cefadroxil, two cephalosporins that are eliminated via renal OAT1/OAT3 and are substrates of PEPT1/PEPT2, with and without 1,25(OH)2 D3 treatment. The area under the plasma concentration-time curve (AUC) of cefdinir or cefadroxil after 1,25(OH)2 D3 treatment was increased significantly because of decreased clearance (CL). Both kidney uptake and cumulative urinary recovery were significantly decreased, whereas liver uptake and fecal recovery remained unchanged in 1,25(OH)2 D3 -treated rats. Similar changes in AUC and CL were observed for both drugs upon coadministration of probenecid, the OAT inhibitor. Oral availability of cefdinir and cefadroxil remained unchanged with 1,25(OH)2 D3 treatment, suggesting lack of a role for intestinal rPEPT1. Rather, reduction of rOAT1/rOAT3 mRNA expression in kidney with 1,25(OH)2 D3 -treatment was observed, confirmed by decreased function in MDCKII cells overexpressing human OAT1 and OAT3. These composite results suggest that 1,25(OH)2 D3 treatment reduces cefdinir and cefadroxil clearances by diminution of renal OAT1/OAT3 expression, implicating a role for 1,25(OH)2 D3 in eliciting transporter-based drug interactions.

Disintegrants combination: development and optimization of a cefadroxil fast disintegrating tablet.

Fast Disintegrating Tablets (FDTs) is a rapidly growing dosage form preferred for special population (pediatric, geriatric and psychotic patients). It is also developed with the aim of improving bioavailability and patient compliance. During the present study, cefadroxil fast disintegrating tablets formulations (n=9) were designed and optimized by central composite design with two independent variables (croscarmellose and crospovidone) using design expert® software. The effects of independent variables on formulation properties such as friability, hardness, in vitro dispersion and disintegration were assessed by drawing response surface graphs with design expert® software. Tablets were assessed for pharmacopeial and non-pharmacopeial parameters to ensure the quality of compressed tablets. Among all formulations, F3, F8 and F9 have shown better results. The formulation F9 containing 15mg croscarmellose and 33.075mg crospovidone showed good pharmacotechnical attributes as well as shelf life. F 9 showed improved dissolution with t90% of> 2 min and will lead to better bioavailability.

Sistema actual per obtenir cefadroxil 250 mg/5 mL oral / No disponible

No disponible

In vivo absorption and disposition of cefadroxil after escalating oral doses in wild-type and PepT1 knockout mice.

PURPOSE: To determine the effect of PepT1 on the absorption and disposition of cefadroxil, including the potential for saturable intestinal uptake, after escalating oral doses of drug. METHODS: The absorption and disposition kinetics of [3H]cefadroxil were determined in wild-type and PepT1 knockout mice after 44.5, 89.1, 178, and 356 nmol/g oral doses of drug. The pharmacokinetics of [3H]cefadroxil were also determined in both genotypes after 44.5 nmol/g intravenous bolus doses. RESULTS: PepT1 deletion reduced the area under the plasma concentration-time profile (AUC0-120) of cefadroxil by 10-fold, the maximum plasma concentration (Cmax) by 17.5-fold, and increased the time to reach a maximum plasma concentration (Tmax) by 3-fold. There was no evidence of nonlinear intestinal absorption since AUC0-120 and Cmax values changed in a dose-proportional manner. Moreover, the pharmacokinetics of cefadroxil were not different between genotypes after intravenous bolus doses, indicating that PepT1 did not affect drug disposition. Finally, no differences were observed in the peripheral tissue distribution of cefadroxil (i.e., outside gastrointestinal tract) once these tissues were corrected for differences in perfusing blood concentrations. CONCLUSIONS: The findings demonstrate convincingly the critical role of intestinal PepT1 in both the rate and extent of oral administration for cefadroxil and potentially other aminocephalosporin drugs.

Oral availability of cefadroxil depends on ABCC3 and ABCC4.

Some cephalosporins, such as cefadroxil, are orally available. H(+)-coupled peptide transporter 1 mediates the transport of cephalosporins across the apical membrane of enterocytes. It is not known which mechanism(s) is responsible for the subsequent transport of cephalosporins across the basolateral membrane toward the circulation. We have tested whether ATP-binding cassette (ABC) transporters ABCC3 and/or ABCC4 are involved in the latter process. Transport experiments with plasma membrane vesicles expressing these transporters were used to determine whether ABCC3 and ABCC4 can transport cephalosporins in vitro. The involvement of Abcc3 and Abcc4 in the transport of cefadroxil from enterocytes was subsequently studied using intestinal explants from wild-type, Abcc3(-/-), Abcc4(-/-), and Abcc3(-/-)/Abcc4(-/-) mice in an Ussing chamber setup. Finally, appearance of cefadroxil in portal blood was investigated in vivo after intrajejunal administration of cefadroxil in wild-type, Abcc3(-/-), Abcc4(-/-), and Abcc3(-/-)/Abcc4(-/-) mice. ABCC3- and ABCC4-mediated transport of estradiol-17ß-glucuronide was dose-dependently inhibited by cephalosporins in vesicular transport experiments. Furthermore, transport of cefadroxil by ABCC3 and ABCC4 was saturable with K(m) values of 2.5 ± 0.7 and 0.25 ± 0.07 mM, respectively. Transport of cefadroxil from the apical to the basolateral side of jejunal tissue explants was unchanged in Abcc3(-/-) but significantly reduced (approximately 2-fold) in Abcc4(-/-) and Abcc3(-/-)/Abcc4(-/-) when compared with wild-type tissue. Upon instillation of cefadroxil in the jejunum, portal and peripheral blood concentrations were similar in Abcc3(-/-) and Abcc4(-/-) but approximately 2-fold reduced in Abcc3(-/-)/Abcc4(-/-) compared with wild-type mice. Our data demonstrate that intestinal absorption of cefadroxil depends partly on ABCC3 and ABCC4.

Phase transited and vapor-induced dual capsular system (DCS) for achieving delayed and osmotic release of cefadroxil.

In the present study, an intestinal pH, disintegrating and non-disintegrating dual capsular system using formaldehyde vapor and phase transition technique, respectively, was developed to achieve delayed as well as improved osmotic flow for the model drug cefadroxil. Formaldehyde vapor was used to attain gastric resistance to the outer gelatin capsule, which disintegrated at the intestinal pH to give a non-disintegrating asymmetric membrane capsule (AMC). The AMC was prepared via dry phase inversion process. The effects of different formulation variables were studied based on 2³ factorial design, namely, level of osmogen, ethylcellulose, and pore former, apart from studying the effects of varying osmotic pressure, agitation intensity, and intentional defect on drug release. Scanning electron microscopy showed an outer dense non-porous and an inner lighter porous region for the prepared asymmetric membrane. Statistical test was applied for in-vitro drug release at P > 0.05. The best formulation in the design closely corresponded to the extra design checkpoint formulation by a similarity (f2) value of 95.28. The drug release was independent of the agitation intensity and intentional defect of the film but dependent on the osmotic pressure of the dissolution medium. The release kinetics followed zero-order, and mechanism of release was Fickian diffusion.

Distribution of glycylsarcosine and cefadroxil among cerebrospinal fluid, choroid plexus, and brain parenchyma after intracerebroventricular injection is markedly different between wild-type and Pept2 null mice.

The purpose of this study was to define the cerebrospinal fluid (CSF) clearance kinetics, choroid plexus uptake, and parenchymal penetration of PEPT2 substrates in different regions of the brain after intracerebroventricular administration. To accomplish these objectives, we performed biodistribution studies using [(14)C]glycylsarcosine (GlySar) and [(3)H]cefadroxil, along with quantitative autoradiography of [(14)C]GlySar, in wild-type and Pept2 null mice. We found that PEPT2 deletion markedly reduced the uptake of GlySar and cefadroxil in choroid plexuses at 60 mins by 94% and 82% (P<0.001), respectively, and lowered their CSF clearances by about fourfold. Autoradiography showed that GlySar concentrations in the lateral, third, and fourth ventricle choroid plexuses were higher in wild-type as compared with Pept2 null mice (P<0.01). Uptake of GlySar by the ependymal-subependymal layer and septal region was higher in wild-type than in null mice, but the half-distance of penetration into parenchyma was significantly less in wild-type mice. The latter is probably because of the clearance of GlySar from interstitial fluid by brain cells expressing PEPT2, which stops further penetration. These studies show that PEPT2 knockout can significantly modify the spatial distribution of GlySar and cefadroxil (and presumably other peptides/mimetics and peptide-like drugs) in brain.

Phase Transited Asymmetric Membrane Capsule: A Means for Achieving Delayed and Controlled Osmotic Flow.

In the present study, a phase transited nondisintegrating polymeric capsular system in achieving delayed as well as improved osmotic flow for the model drug cefadroxil was developed. Asymmetric membrane capsule (AMC) was prepared by precipitation of asymmetric membrane (AM) on the fabricated glass mold pins via wet phase inversion process. Effect of different formulation variables were studied based on 23 factorial design, namely, level of osmogen, ethylcellulose, pore former, apart from studying the effect of varying osmotic pressure on drug release. Scanning electron microscopy showed an outer dense non-porous region and an inner lighter porous region for the prepared AMC. Statistical test (Dunnett multiple comparison test) was applied for in vitro drug release (n=6) at P < 0.05. The best formulation in the design closely corresponded to the extra design checkpoint formulation by a similarity factor (f2) of 98.91, and a difference factor (f1) of 2.17. The drug release was independent of agitation intensity but dependent on the osmotic pressure of the dissolution medium. The release kinetics followed Higuchi model, and mechanism of release was Fickian diffusion.

Bioequivalence study of two oral formulations of cefadroxil in healthy volunteers.

Two different cefadroxil (CAS 50370-12-2) formulations were evaluated for their relative bioavailability in 24 healthy volunteers who received a single 500 mg oral dose of each preparation. An open, randomized clinical trial designed as a two-period crossover study with a 7-day washout period between doses was employed. Plasma samples for assessments of their cefadroxil concentration by HPLC-UV were obtained over 8 h after administration. Values of 48.94 +/- 10.18 pg x h/ml for test, and 48.51 +/- 9.02 microg x h/ml for the reference preparation AUC(0-t) demonstrate a nearly identical extend of drug absorption. Maximum plasma concentration Cmax of 16.04 +/- 4.94 microg/ml and 16.01 + 4.02 microg/ml achieved for the test and reference preparations did not differ significantly. The parametric 90% confidence intervals (CI) of the mean of the difference (test-reference) between log-transformed values of the two formulations were 96.80% to 104.51% and 92.01% to 107.00% for AUC(0-t) and Cmax, respectively. Since for both AUC(0-t) or Cmax the 90% CI values are within the interval proposed by the Food and Drug Administration, the test product is bioequivalent to the reference product for both the rate and extent of absorption after single dose administration.