Some representative drugs

A brief description is given of representative drugs from some of these areas 

Alimentary system Cardiovascular system Central nervous system Analgesics 

Anti-inflammatory agents Respiratory system Growth and metabolism Fertility 

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Figure 1. Chemical structure and skin permeation rate of some representative drugs (Data adapted from Reference 13).

Scheme 11.2 shows some representative halogenation reactions. Entries 1 and 2 involve Lewis acid-catalyzed chlorination. Entry 3 is an acid-catalyzed chlorination using NCS as the reagent. Entry 4 shows a high-yield chlorination of acetanilide by i-butyl hypochlorite. This seems to be an especially facile reaction, since anisole is not chlorinated under these conditions, and may involve the A-chloroamide as an intermediate. Entry 5 describes a large-scale chlorination done with NCS. The product was used for the synthesis of sulamserod, a drug candidate. 

Some representative /3-lactam drugs used in veterinary practice are benzylpenicillin (17), ampicillin (18), amoxicillin (19), cloxacillin (20), penethamate (21) and cephalexin (22). 

This family is almost cosmopolitan but chiefly tropical with some representatives in the temperate zones. It is noted for many ornamentals, some species that yield rubber (Funlumia, Landol-phia), and several useful drugs (Strophanlhus, Acokanlhera, Catha-ranthus, Rauvolfta). Many arc toxic. 

Another way to assess ion channel conductance is to use artificial phospholipid vesicles (liposomes) as cell models. These structures (described in more detail in the next chapter) are commonly used to transport vaccines, drugs, enzymes, or other substances to target cells or organs. The vesicles, which are several hundred nanometres in diameter, do not suffer from interference from residual natural ion channel peptides or ionophores, unlike purified natural cells. A liposome model was used to test the ion transport behaviour of the redox-active hydraphile 12.36. The compound transports Na+ and the process can also be monitored using 23Na NMR spectroscopy.26 The presence of the ferrocene-derived group in the central relay allows the ion transport to be redox-controlled - oxidation to ferrocinium completely prevents Na+ transport for electrostatic reasons. Some representative data from a planar bilayer measurement is shown for hydraphile 12.36 in Figure 12.16. 

Pharmaceutical products can be readily classified and arranged by their therapeutic functions. Classification according to chemical criteria is more difficult, because the pharmaceutical industry employs more complicated steps in its manufacturing processes than most other chemical industries. In this section, we will briefly describe the various therapeutic classes of drugs and we will also include the reactions involved in the synthesis of some representative examples of drug substances. 

The release of drug molecules from this type of CrDDSs may be controlled at a preprogrammed rate by controlling the loading level and the polymer solubility of the drug and its diffusivity in the polymer matrix. Several CrDDSs of this type have been successfully marketed for therapeutical uses, and some representatives are outlined later for illustration. 

Some true (undissociated, corrected) partition coefficients of representative drug molecules ranging from —2.26 to -1-15.69 are shown in Table 1. 

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