Clark’s Rule

Weight (somewhat more precise is Clark s rule) ... 

When considering body weight, the usual doses for infants and children is given by the following rule Clark s Rule... 

Clark s RuLe Divide the weight in pounds by 150 to give an approximate fraction of an adulf s dose. For a 75-pound (34 kg) child the dose would be 75 divided by 150, or 1/2 the adult dose. 

Clark (1937) further expanded Haber s rule for the action of a number of drugs ... 

So, the perfect fit of Haber s rule to the carcinogenic action of 4-DAB suggested that threshold concentration (c ) and minimum time of response (i ) were (in Clark s words) so small as not to produce a measurable error. 

Iminium ion-alkene cyclizations accomplished under standard Eschweiler-Clarke methylation conditions have been employed to prepare five-, six- and seven-membered azacycles (Scheme 25).57,58 It is important to note that under identical conditions amines (62) and (63) did not cyclize but afforded the corresponding IVjV-dimethylamines. With regard to the alkene participant these results are in full accord with Baldwin s rules for ring formation.2 However, the formation of pyrrolidine (61) demonstrates that 5-endo-trig cyclizations2 can take place with respect to the iminium ion n-participant. The observed regioselectivity and the failure of (63) to cyclize are in accord with obligatory formation of an intermediate with tertiary carbocation character. 

Table I. Bioavailability enhancing properties of agrochemicals according to Briggs [4], Tice [5], and Clarke-Delaney [6-7] compared to pharmaceuticals based on Lipinsky s Rule of Five [3].

Proton adsorption/desorption was utilized by Clark and Sutin to control electron injection yields and probe Gerisher s distributions at planar rutile electrodes. More recently, Gratzel and co-workers found that excited-state electron injection from tetrakis(4-carboxyphenyl)porphyrinato]Zn to colloidal Ti02 particles was negligible at pH > 8 but increased substantially when the pH was lowered [211]. However, in this case it was difficult to rule out a trivial mechanism where the sensitizer simply desorbed from the surface at higher pH. 

---