Spectral Determination of Microdissociation Constants

Nuclear magnetic resonance studies of the acid–base chemistry of amino acids and peptides. III. Determination of the microscopic and macroscopic acid dissociation constants of α,ω-diaminocarboxylic acids

“…The results obtained from the individual titration curves are presented in Table 1. Also presented in Table 1 tution of [5] into [4] and [4] into [5]. The micro- Table 2 whereas pkI3 and ~k 1 3~ both differ by 0.14 of a pk unit.…”

“…Thus, the microconstants of cysteine, tyrosine, and related molecules containing a sulfhydryl or a phenolic group have been determined by se1e1;tively monitoring the titration of the sulfhydryl or the phenolic group by uv spectroscopy (1)(2)(3)(4)(5). However, the microscopic acid-base chemistry of amino acids containing two acidic groups of the same type is not amenable to study by absorption spectroscopy, and thus the only microconstants which have been reported for amino acids such as lysine and glutamic acid are those which have been estimated from their potentiometrically determined macroconstants and those of related molecules (6, 7).…”

Efficient Pharmacokinetic Modeling of Complex Clinical Dosing Regimens: The Universal Elementary Dosing Regimen and Computer Algorithm EDFAST

“…More importantly however, dt) is also the basis of the solutions for all complex dosing regimens in all linear first-order compartmental models. 1. The definitions of more elaborate models with N, compartments (including various absorption and/or more body compartments) are similar to that of the one-compartment model (eq 1) except that there is a separate defining rate equation for each compartment, each rate equation may have several terms (one representing each route of entry to or exit from the compartment), and uedrs may be administered into all of the compartments.…”

“…For acute antiarrhythmic prophylaxis after suspected myocardial infarction, a 75-mg "slow bolus" loading injection followed by a 2-mglmin maintenance infusion are standard therapy. In addition, to overcome a subtherapeutic hiatus 30 min after the injection, current recommendations9 include one of the following supplemental lidocaine regimens: (1) nil; (2) 150 mg as three 50-mg "slow boluses" given every 5 min over a period of 1 min each; (3) 114 mg as an additional infusion a t a rate of 6.33 mg/min (for a total rate of 8.33 mg/min) during the first 18 min; or (4) 150 mg as an additional exponentially declining infusion starting at a rate of 3.33 mg/min and tapering to 0 with a 31-min halflife (Lido-1 to Lido-4, Table I). Assuming a two-compartment model with V1 = 35 L, k, = 0.024/min, k12 = 0.066/min, and k21 = 0.038/min to describe average lidocaine kinetics,'& an indication of the relative efficacy and toxicity of these regi- Table I).…”

“…The following integer functions of time are helpful here, where the notation [XI denotes the greatest integer s x ( Figure 3). 1. The function n,(t) is the number of infusions of the 0 uedr that have been started a t or before time t:…”