ELECTROPHORETIC EVALUATION OF THE MOBILITY OF DRUGS SUITABLE FOR IONTOPHORESIS

Iontophoresis is the process of increasing the penetration of drugs fo r therapeuric purposes using DC electricity. Tile most important facto r for iontophoresis is the formation of drug ions in solution. On this basis, the penetration of any drug applied by iontophoresis might be maximized at an optimal pH. Seven medications were investigated: acycl ovix, methylprednisolone sodium succinate, metronidazole, dexamethason e sodium phosphate, minoxidil, lidocaine hydrochloride, and adenine ar abinoside monophosphate. Using techniques of paper electrophoresis, we evaluated the influence of pH on the mobility (mu) of the drugs in ph osphate buffers at pH 5, 7, and 9. The mu-values were calculated after detecting the drugs on paper with ultraviolet light. The results indi cate that the seven drugs had higher mu-values usually at one, but som etimes at two, of the pH values studied. This study suggests that a va riation in pH might alter the maximum ionization, and therefore, the o ptimal mobility for these seven drugs, as well as other drugs, suited to iontophoresis.