Bioavailability of bacampicillin and talampicillin, two oral prodrugs of ampicillin

Age-related modifications in CYP-dependent drug metabolism: role of stress

Accumulating clinical evidence indicates extensive inter-individual variations in the effectiveness and adverse effects of standard treatment protocols, which are largely attributed to the multifactorial regulation of the hepatic CYP-dependent drug metabolism that is connected with either transcriptional or post-translational modifications. Age and stress belong to the most important factors in CYP gene regulation. Alterations in neuroendocrine responses to stress, which are associated with modified hypothalamo-pituitary-adrenal axis function, usually accompany ageing. In this light, ageing followed by a decline of the functional integrity of organs, including liver, a failure in preserving homeostasis under stress, increased morbidity and susceptibility to stress, among others, holds a determinant role in the CYP-catalyzed drug metabolism and thus, in the outcome and toxicity of pharmacotherapy. Modifications in the drug metabolizing capacity of the liver with age have been reported and in particular, a decline in the activity of the main CYP isoforms in male senescent rats, indicating decreased metabolism and higher levels of the drug-substrates in their blood. These factors along with the restricted experience in the use of the most medicines in childhood and elderly, could explain at an extent the inter-individual variability in drug efficacy and toxicity outcomes, and underscore the necessity of designing the treatment protocols, accordingly.

Physicochemical property trends of marketed prodrugs

Many prodrug reviews describe specific examples of the successful application of prodrug technology to produce blockbuster drugs, such as simvastatin, omeprazole, acyclovir and enalapril. These reviews are helpful to understand the previous success stories and case histories of prodrug technology. The aim of the current review seeks to more clearly define quantitative trends in the changes in the physicochemical property parameters between the successful prodrug and the active parent molecule. This information can serve to guide medicinal chemists toward more successful pharmaceutical prodrugs in the future.

Intracellular protein labeling with prodrug-like probes using a mutant β-lactamase tag

Intracellular protein labeling with small molecular probes that do not require a washing step for the removal of excess probe is greatly desired for real-time investigation of protein dynamics in living cells. Successful labeling of proteins on the cell membrane has been performed using mutant β-lactamase tag (BL-tag) technology. In the present study, intracellular protein labeling with novel cell membrane permeable probes based on β-lactam prodrugs is described. The prodrug-based probes quickly permeated the plasma membranes of living mammalian cells, and efficiently labeled intracellular proteins at low probe concentrations. Because these cell-permeable probes were activated only inside cells, simultaneous discriminative labeling of intracellular and cell surface BL-tag fusion proteins was attained by using cell-permeable and impermeable probes. Thus, this technology enables adequate discrimination of the location of proteins labeled with the same protein tag, in conjunction with different color probes, by dual-color fluorescence. Moreover, the combination of BL-tag technology and the prodrug-based probes enabled the labeling of target proteins without requiring a washing step, owing to the efficient entry of probes into cells and the fast covalent labeling achieved with BL-tag technology after bioactivation. This prodrug-based probe design strategy for BL-tags provides a simple experimental procedure with application to cellular studies with the additional advantage of reduced stress to living cells.

Ampicillin concentrations in radicular cysts following a single oral administration of bacampicillin

1. Ampicillin concentrations in cyst wall (wall) and cyst fluid (fluid) of radicular cyst and serum following a single oral administration of bacampicillin (equivalent to 500 mg of ampicillin) were measured by a paper disk method. 2. The mean peak concentrations of ampicillin in wall, fluid, and serum occurred at identical times, 1.5 hr, and were 2.39 micrograms/g, 0.77, and 10.24 micrograms/ml, respectively. 3. Mean ampicillin concentration ratios of wall/serum, fluid/serum, and fluid/wall at the peak time were 0.23, 0.07, and 0.40, respectively. 4. Mean ampicillin concentrations in wall and fluid at the peak time exceeded MIC (minimum inhibitory concentration) for 90% (0.5 microgram/ml) for clinically isolated strains of alpha-hemolytic Streptococci.

Ampicillin concentrations in human radicular granuloma following a single oral dose of bacampicillin

Ampicillin concentrations in human serum and radicular granulomas of 42 patients were determined after a single oral dose of bacampicillin (equivalent to 500 mg of ampicillin). Although wide variations were found among both serum and radicular granuloma ampicillin concentrations, measurable concentrations were found in all cases. The mean peak ampicillin concentrations in serum and radicular granulomas occurred at identical times, 1.5 hours, and were 11.19 micrograms/mL (range, 1.30 to 21.00 micrograms/mL) and 5.12 micrograms/g (range, 0.50 to 10.50 micrograms/g), respectively. The mean radicular granuloma/serum ampicillin concentration ratio at the peak time was 0.42. Ampicillin concentrations in radicular granulomas exceeded most of the minimum inhibitory concentrations for bacteria commonly isolated from odontogenic infections.

Ampicillin concentrations in human serum and periodontal membrane following a single oral administration of talampicillin

1. Ampicillin concentrations in human serum and periodontal membrane after a single oral administration of talampicillin (500 mg) were assayed by the agar diffusion (paper disc) method. 2. The peak times of serum and periodontal membrane were identical, being 150 min after administration. 3. The peak concentrations of serum and periodontal membrane were 7.81 micrograms/ml and 4.11 micrograms/g, respectively. 4. The mean ratio of periodontal membrane to serum concentration at the peak time was 0.53.

Ampicillin concentrations in human serum, gingiva, mandibular bone, dental follicle, and dental pulp following a single oral administration of bacampicillin

Ninety-six patients who underwent the extraction of impacted mandibular third molars in a nonfasting state were given a single oral dose of bacampicillin preoperatively. Specimens of serum from venous blood (n = 107), gingiva (n = 57), mandibular bone (n = 68), dental follicle (n = 56), and dental pulp (n = 43) were obtained during the operation and assayed for ampicillin content. The mean peak concentrations in serum, gingiva, mandibular bone, dental follicle, and dental pulp all occurred approximately 90 minutes after administration. The concentration ratios of the tissues to the corresponding serum at the peak time were 0.50, 0.20, 0.34, and 0.61, respectively. Bacampicillin showed good absorption by the intestine, and sufficient concentrations of the resulting metabolite, ampicillin, were found in the oral tissues.

Ampicillin concentrations in human serum and periodontal membrane following a single oral administration of bacampicillin

Ampicillin concentrations in human serum and periodontal membrane after a single oral administration of bacampicillin (500 mg) were assayed by the agar diffusion (paper disc) method. The peak times of serum and periodontal membrane were nearly identical, being approx. 90 min after administration. The peak concentrations of serum and periodontal membrane were 12.81 micrograms/ml and 6.97 micrograms/g, respectively. The concentration ratio of periodontal membrane to serum at the peak time was 0.56.