Cefadroxil. A review of its antibacterial, pharmacokinetic and therapeutic properties in comparison with cephalexin and cephradine

In Vitro In Vivo Extrapolation and Bioequivalence Prediction for Immediate-Release Capsules of Cefadroxil Based on a Physiologically-Based Pharmacokinetic ACAT Model

Physiologically based pharmacokinetic (PBPK) modeling is a mechanistic concept, which helps to judge the effects of biopharmceutical properties of drug product such as in vitro dissolution on its pharmacokinetic and in vivo performance. With the application of virtual bioequivalence (VBE) study, the drug product development using model-based approach can help in evaluating the possibility of extending BCS-based biowaiver. Therefore, the current study was intended to develop PBPK model as well as in vitro in vivo extrapolation (IVIVE) for BCS class III drug i.e. cefadroxil. A PBPK model was created in GastroPlus™ 9.8.3 utilizing clinical data of immediate-release cefadroxil formulations. By the examination of simulated and observed plasma drug concentration profiles, the predictability of the proposed model was assessed for the prediction errors. Furthermore, mechanistic deconvolution was used to create IVIVE, and the plasma drug concentration profiles and pharmacokinetic parameters were predicted for different virtual formulations with variable cefadroxil in vitro release. Virtual bioequivalence study was also executed to assess the bioequivalence of the generic verses the reference drug product (Duricef®). The developed PBPK model satisfactorily predicted Cmax and AUC0-t after cefadroxil single and multiple oral dose administrations, with all individual prediction errors within the limits except in a few cases. Second order polynomial correlation function obtained accurately predict in vivo drug release and plasma concentration profile of cefadroxil test and reference (Duricef®) formulation. The VBE study also proved test formulation bioequivalent to reference formulation and the statistical analysis on pharmacokinetic parameters reported 90% confidence interval for Cmax and AUC0-t in the FDA acceptable limits. The analysis found that a validated and verified PBPK model with a mechanistic background is as a suitable approach to accelerate generic drug development.

Cefadroxil and cephalexin pharmacokinetics and pharmacodynamics in children with musculoskeletal infections

Cephalexin, a first-generation cephalosporin, is the first-line oral therapy for children with musculoskeletal infections due to methicillin-susceptible Staphylococcus aureus (MSSA). Cefadroxil, a similar first-generation cephalosporin, is an attractive alternative to cephalexin given its longer half-life. In this study, we describe the comparative pharmacokinetics (PK) and pharmacodynamics (PD) of cephalexin and cefadroxil in children with musculoskeletal infections. Children aged 6 months to 18 years with a musculoskeletal infection were enrolled in a prospective, open-label, crossover PK study and given single oral doses of cefadroxil (50-75 mg/kg up to 2,000 mg) and cephalexin (50 mg/kg up to 1,375 mg). Population PK models were developed and used for dosing simulations. Our primary PD target was the achievement of free antibiotic concentrations above the minimum inhibitory concentration (fT >MIC) for 40% of the day for MICs ≤ 4 mg/L. PK of cephalexin (n = 15) and cefadroxil (n = 14) were best described using a one-compartment, first-order absorption model, with a lag time component for cefadroxil. PK parameters were notable for cefadroxil's longer half-life (1.61 h) than cephalexin's (1.10 h). For pediatric weight bands, our primary PD target was achieved by cephalexin 25 mg/kg/dose, maximum 750 mg/dose, administered three times daily and cefadroxil 40 mg/kg/dose, maximum 1,500 mg/dose, administered twice daily. More aggressive dosing was required to achieve higher PD targets. Among children with musculoskeletal infections, oral cephalexin and cefadroxil achieved PD targets for efficacy against MSSA. Given less frequent dosing, twice-daily cefadroxil should be further considered as an alternative to cephalexin for oral step-down therapy for serious infections due to MSSA.

Identification of new inhibitors of NS5 from dengue virus using saturation transfer difference (STD-NMR) and molecular docking studies

The rapid spread of dengue virus has now emerged as a major health problem worldwide, particularly in tropical and sub-tropical regions. Nearly half of the human population is at risk of getting infection. Among the proteomes of dengue virus, nonstructural protein NS5 is conserved across the genus Flavivirus. NS5 comprises methyltransferase enzyme (MTase) domain, which helps in viral RNA capping, and RNA-dependent RNA polymerase (RdRp) domain, which is important for the virus replication. Negative modulation of NS5 decreases its activity and associated functions. Despite recent advances, there is still an immense need for effective approaches toward drug discovery against dengue virus. Drug repurposing is an approach to identify the new therapeutic indications of already approved drugs, for the treatment of both common and rare diseases, and can potentially lower the cost, and time required for drug discovery and development. In this study, we evaluated 75 compounds (grouped into 15 mixtures), including 13 natural compounds and 62 drugs, by using biophysical methods, for their ability to interact with NS5 protein, which were further validated by molecular docking and simulation studies. Our current study led to the identification of 12 ligands, including both 9 US-FDA approved drugs and 3 natural products that need to be further studied as potential antiviral agents against dengue virus.

Cefadroxil Comparable to Cephalexin: Minimum Inhibitory Concentrations among Methicillin-Susceptible Staphylococcus aureus Isolates from Pediatric Musculoskeletal Infections

Cephalexin and cefadroxil are oral first-generation cephalosporins used to treat methicillin-susceptible Staphylococcus aureus (MSSA) infections. Despite its shorter half-life, cephalexin is more frequently prescribed, although cefadroxil is an appealing alternative, given its slower clearance and possibility for less frequent dosing. We report comparative MIC distributions for cefadroxil and cephalexin, as well as for oxacillin, cephalothin, ceftaroline, and cefazolin, for 48 unique clinical MSSA isolates from pediatric patients with musculoskeletal infections. Both cefadroxil and cephalexin had MIC50 values of 2 μg/mL and MIC90 values of 4 μg/mL. MIC50s for oxacillin, cephalothin, and ceftaroline were ≤0.25 μg/mL, and cefazolin's MIC50 was 0.5 μg/mL. While cefadroxil and cephalexin MICs are higher than those for other active agents, the distributions of MICs for cefadroxil and cephalexin are statistically equivalent, suggesting similar in vitro MSSA activities. Cefadroxil should be further considered an alternative agent to cephalexin, although additional work is needed to identify the optimal dose and frequency of these antibiotics for the treatment of serious MSSA infections. IMPORTANCE Cephalexin and cefadroxil are oral antibiotics that are used to treat serious infections due to the bacteria MSSA. While cephalexin is used more commonly, cefadroxil is excreted from the body more slowly; this generally allows patients to take cefadroxil less frequently than cephalexin. In this study, we compared the abilities of cefadroxil, cephalexin, and several other representative intravenous antibiotics to inhibit the growth of MSSA in the laboratory. Bacterial samples were obtained from children with bone, joint, and/or muscle infections caused by MSSA. We found that cefadroxil and cephalexin inhibited the growth of MSSA at similar concentrations, suggesting similar antibacterial potencies. The selected intravenous antistaphylococcal antibiotics generally inhibited bacterial growth with lower antibiotic concentrations. Based on these results, cefadroxil should be further considered an alternative oral antibiotic to cephalexin, although future research is needed to identify the optimal dose and frequency of these antibiotics for serious infections.

Physiologically Based Pharmacokinetic Modeling of Cefadroxil in Mouse, Rat, and Human to Predict Concentration-Time Profile at Infected Tissue

The aim of this study was to develop physiologically based pharmacokinetic (PBPK) models capable of simulating cefadroxil concentrations in plasma and tissues in mouse, rat, and human. PBPK models in this study consisted of 14 tissues and 2 blood compartments. They were established using measured tissue to plasma partition coefficient (K_p) in mouse and rat, absolute expression levels of hPEPT1 along the entire length of the human intestine, and the transporter kinetic parameters. The PBPK models also assumed that all the tissues were well-stirred compartments with perfusion rate limitations, and the ratio of the concentration in tissue to the unbound concentration in plasma is identical across species. These PBPK models were validated strictly by a series of observed plasma concentration–time profile data. The average fold error (AFE) and absolute average fold error (AAFE) values were all less than 2. The models’ rationality and accuracy were further demonstrated by the almost consistent V_ss calculated by the PBPK model and noncompartmental method, as well as the good allometric scaling relationship of V_ss and CL. The model suggests that hPEPT1 is the major transporter responsible for the oral absorption of cefadroxil in human, and the plasma concentration–time profiles of cefadroxil were not sensitive to dissolution rate faster than T_85% = 2 h. The cefadroxil PBPK model in human is reliable and can be used to predict concentration–time profile at infected tissue. It may be useful for dose selection and informative decision-making during clinical trials and dosage form design of cefadroxil and provide a reference for the PBPK model establishment of hPEPT1 substrate.

Repurposing of Antimicrobial Agents for Cancer Therapy: What Do We Know?

The substantial costs of clinical trials, the lengthy timelines of new drug discovery and development, along the high attrition rates underscore the need for alternative strategies for finding quickly suitable therapeutics agents. Given that most approved drugs possess more than one target tightly linked to other diseases, it encourages promptly testing these drugs in patients. Over the past decades, this has led to considerable attention for drug repurposing, which relies on identifying new uses for approved or investigational drugs outside the scope of the original medical indication. The known safety of approved drugs minimizes the possibility of failure for adverse toxicology, making them attractive de-risked compounds for new applications with potentially lower overall development costs and shorter development timelines. This latter case is an exciting opportunity, specifically in oncology, due to increased resistance towards the current therapies. Indeed, a large body of evidence shows that a wealth of non-cancer drugs has beneficial effects against cancer. Interestingly, 335 drugs are currently being evaluated in different clinical trials for their potential activities against various cancers (Redo database). This review aims to provide an extensive discussion about the anti-cancer activities exerted by antimicrobial agents and presents information about their mechanism(s) of action and stage of development/evaluation.

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.

Characteristics, Properties and Analytical Methods of Cefadroxil: A Review

Infections are the second leading cause of mortality worldwide and there are many reasons justifying the need for further studies of antimicrobial agents. Cefadroxil is a drug that has bactericidal activity and broad spectrum of action. Quantitative analyzes about cefadroxil are essential for the understanding of bioavailability, bioequivalence, and therapeutic control, which will ensure the product's characteristics and patients' safety. Thus, this study highlights a brief literature review about the drug and the existing methods developed for the determination of cefadroxil found in official and scientific papers. According to the methods found in literature, liquid chromatography and spectrophotometry of absorption in the ultraviolet region prevailed over the others. Importantly, most of the solvents used for the development of the described analytical methods are toxic to the environment, making it necessary to educate researchers and pharmaceutical companies to use nontoxic solvents to provide environmental-friendly methods and better benefits to equipments and mainly to analysts.

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 β-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 β-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.

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.

Determination of cefadroxil in rat plasma and urine using LC-MS/MS and its application to pharmacokinetic and urinary excretion studies

A simple, rapid, and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of cefadroxil, a first-generation cephalosporin, in rat plasma and urine. Rat samples were deproteinized with methanol, and then injected into the LC-MS/MS system (electro-spray ionization, positive mode) for quantification. Drugs were separated on a Synergi™ 4 μm Polar-RP 80A column (150 mm × 2.0 mm, 4 μm) with a mixture of 0.1% formic acid and methanol (62:38, v/v) as the mobile phase at 0.2 mL/min. Detection was performed using multiple reaction-monitoring modes at m/z 364.1→208.1 (for cefadroxil) and m/z 368.1→174.2 (for cefaclor, the internal standard). Method was specific and linear over the concentration range of 10-10,000 ng/mL. Validation parameters for cefadroxil, including accuracy, precision, absolute matrix effect, and stability in rat plasma and urine, were acceptable according to the biological method validation guidelines of the FDA (2001) [16]. Cefadroxil levels in plasma up to 1440 min or 480 min and urine up to 96 h were quantifiable following oral and intravenous cefadroxil administrations to rats at a dose of 2mg/kg, each, suggesting that the method is appropriate for routine pharmacokinetic studies including urinary recovery in rats.

Impact of lipopolysaccharide-induced inflammation on the disposition of the aminocephalosporin cefadroxil

The purpose of this study was to determine if the disposition of cefadroxil, an α-amino-containing β-lactam antibiotic, changes during lipopolysaccharide (LPS)-induced acute inflammation. Six hours after LPS or saline treatment, mice received 1 nmol/g cefadroxil intravenously along with inulin for glomerular filtration rate (GFR) determination. Serial blood samples, along with tissue and urine samples, were collected at predetermined time points. In order to determine inflammation-induced changes in GFR, renal tubular secretion, and reabsorption, it was necessary to coadminister 70 mg/kg probenecid. Changes in the expression of the mRNA of transporters involved in cefadroxil disposition in the kidneys and choroid plexus were also investigated 6 h after LPS treatment. The results demonstrated marked increases in blood, cerebrospinal fluid, and tissue cefadroxil concentrations with LPS treatment. Tissue-to-blood concentration ratios were decreased by 4.6-fold in the choroid plexus and by 2.5-fold in the kidneys during LPS-induced inflammation. Renal, but not choroid plexus, mRNA expression of peptide transporter 2, organic-anion transporter 1 (OAT1), OAT3, and multidrug resistance-associated protein 4 was mildly reduced in LPS-treated mice. The renal clearance of cefadroxil was substantially decreased by LPS treatment (3-fold). GFR was also reduced by 3-fold in LPS-treated mice, but no significant differences in the fractional reabsorption of cefadroxil and renal secretion once normalized by GFR were observed. These findings demonstrated that LPS-induced inflammation has a dramatic effect on the renal excretion of cefadroxil. It appears that changes in transporter expression played a minor role during LPS treatment but that renal dysfunction, associated with GFR reduction, was responsible for the substantial increase in plasma cefadroxil concentration-time profiles.

Relevance of PepT1 in the intestinal permeability and oral absorption of cefadroxil

PURPOSE

To determine the contribution of intestinal PepT1 on the permeability and oral absorption of the β-lactam antibiotic drug cefadroxil.

METHODS

The effective permeability (P eff ) of cefadroxil was evaluated in wild-type and PepT1 knockout mice following in situ single-pass intestinal perfusions. The plasma concentration-time profiles of cefadroxil were also examined after oral gavage.

RESULTS

The P eff (cm/s) of cefadroxil in wild-type mice was 0.49 × 10(-4) in duodenum, 0.80 × 10(-4) in jejunum, 0.88 × 10(-4) in ileum and 0.064 × 10(-4) in colon. The P eff (cm/s) in PepT1 knockout mice was significantly reduced in small intestine, but not in colon, as shown by values of 0.003 × 10(-4), 0.090 × 10(-4), 0.042 × 10(-4) and 0.032 × 10(-4), respectively. Jejunal uptake of cefadroxil was saturable (Km = 2-4 mM) and significantly attenuated by the sodium-proton exchange inhibitor 5-(N,N-dimethyl)amiloride. Jejunal permeability of cefadroxil was not affected by L-histidine, glycine, cephalothin, p-aminohippurate or N-methylnicotinamide. In contrast, cefadroxil permeability was significantly reduced by glycylproline, glycylsarcosine, or cephalexin. Finally, PepT1 ablation resulted in 23-fold reductions in peak plasma concentrations and 14-fold reductions in systemic exposure of cefadroxil after oral dosing.

CONCLUSIONS

The findings are definitive in demonstrating that PepT1 is the major transporter responsible for the small intestinal permeability of cefadroxil as well as its enhanced oral drug performance.

Adverse events associated with the use of oral cephalosporins/cephems

Historically, oral cephalosporins represent one of the most widely used and safest classes of antimicrobials available. Typical adverse events have included nausea, vomiting, diarrhea, and hypersensitivity reactions. Other more serious events such as pseudomembranous colitis, although infrequent, may occur. The exact type and incidence of adverse events varies depending on the cephalosporin being administered. Differences in adverse event profiles may also vary by age of the patient. Reactions are usually not severe and often do not require termination of therapy. The purpose of this review is to present to healthcare providers the historical safety profile of the most commonly used oral cephalosporins.

Comparative bioavailability of two cefadroxil products using serum and urine data in healthy human volunteers

1. The aim of the present study was to assess the bioequivalence of two cefadroxil products, namely Ultracef (a reference product) in the form of a 500 mg capsule (produced by Bristol-Myers Squibb Laboratories, Princeton, NJ, USA) and Roxil (a test product) in the form of a 500 mg capsule (produced by Tabuk Pharmaceutical Manufacturing, Tabuk, Saudi Arabia). 2. The study was performed under US Food and Drug Administration (FDA) guidelines (http://www.fda.gov/cder) on 24 healthy male subjects. Both products were administered orally as a single dose (1 x 500 mg capsule) separated by a 1 week washout period. Following oral administration, blood and urine samples were obtained and analysed for cefadroxil concentrations using a sensitive and specific HPLC assay. 3. There were no statistically significant differences between the two products in either the mean concentration-time profiles or the cumulative urinary excretion of cefadroxil at various times. Similarly, no statistical significance was observed in the pharmacokinetic parameters reflecting rate and extent of drug absorption. The relative extent of drug absorption, assessed by calculating the area under the curve (AUC) ratio for Roxil/Ultracef for 10 h and for infinity was 0.94 with 90% confidence limits (CL) of 0.91-0.98. In agreement with serum data, the average ratio (Roxil/Ultracef) of the cumulative amount of cefadroxil excreted in urine 10 h after the dose was found to be 0.97, with 90% CL of 0.88-1.05. The CL of the AUC and cumulative urinary excretion ratios are within the FDA accepted limits for bioequivalent products (0.80-1.25). 4. These findings show that serum and urine data of cefadroxil are in agreement and indicate that Roxil (the test product) and Ultracef (the reference product) are bioequivalent in terms of the rate and extent of drug absorption.

The effect of pore formers on the controlled release of cefadroxil from a polyurethane matrix

The effect of various pore formers on the controlled release of an antibacterial agent from a polymeric device was examined in order to develop a novel biomaterial that prevents bacterial adhesion and growth on its surface. Cefadroxil was chosen as the model antibiotic and was incorporated into a polyurethane matrix by the solvent-casting method. Polyethylene glycol (PEG) 1450, D-mannitol, or bovine serum albumin (BSA) was used as a pore former. The amount of cefadroxil released from various formulations at 37 degrees C was measured by HPLC. The morphological change of matrices before and after release studies was investigated by scanning electron microscopy (SEM). The duration of antimicrobial activities of matrices against Escherichia coli and Bacillus subtilis was evaluated by measuring the diameters of the inhibition zone. Changing the weight fraction and particle size of the pore formers/drug mixtures could control the release of cefadroxil from the matrix. The release rate of cefadroxil increased as the loading dose of the pore former increased (15<20<25%). Cefadroxil released from these devices exhibited antibacterial activity for 5-6 days. These results imply that an antibiotic-loaded polymeric device that could prevent bacterial infection on its surface can be formulated using appropriate pore formers.

Effect of timing of food on absorption of cefpodoxime proxetil

The effect of a high-fat meal and the timing of this meal on the absorption of a 400-mg oral dose of cefpodoxime proxetil was evaluated in 20 healthy, adult, male volunteers in a four-way crossover study. The area under the plasma concentration-time curve, peak plasma concentration, and urinary recovery were significantly greater (P = .0001) after administration of cefpodoxime proxetil tablets with and 2 hours after a meal relative to dosing under fasted conditions or 1 hour before a meal. The time to peak concentration did not differ significantly among treatments, which suggests that food did not affect the rate of drug absorption. These results indicate that absorption of cefpodoxime proxetil is enhanced when tablets are taken with food or shortly after a meal.

Cefadroxil in the management of facial cellulitis of odontogenic origin

The objectives of this prospective single-blind trial were to compare the efficacy and safety of cefadroxil, 1 gm/day, and cephalexin, 250 mg four times a day, in the treatment of facial cellulitis of odontogenic origin. One hundred sixteen patients were screened for sensitivity to the assigned antibiotic and then randomly assigned treatment groups. Fifty-eight (100%) of the cefadroxil-treated patients and 57 (98%) of the cephalexin-treated patients were considered cured. Adverse reactions were noted in only two cefadroxil-treated patients and one cephalexin-treated patient. One patient from each group discontinued therapy prematurely; the patient who discontinued cephalexin was the only treatment failure in this study. This study found that cefadroxil administered once a day was therapeutically equivalent to cephalexin given four times a day.

Non-linear intestinal absorption kinetics of cefadroxil in the rat

Absorption of cefadroxil in a selective intestinal absorption area (the proximal third of the small intestine) of the anaesthetized rat, at seven initial perfusion concentrations, ranging from 0.01 to 10.0 mg mL-1, is shown to be a non-linear transport mechanism. With the aid of computer-fitting procedures based on differential and integrated forms of Michaelis-Menten equation, Vm and Km values of 36.7-37.3 mg h-1 and 12.0-13.0 mg, respectively, were found. The statistical parameters were better than those obtained both for first-order and for combined Michaelis-Menten and first-order kinetics. There is no evidence for substantial passive diffusion processes. The results reported here, together with allometric considerations and literature data analysis, may help to explain some particular non-linear features of plasma level curves associated with the administration of fairly high oral doses of cefadroxil to humans.