include one or more of primary secondary and tertiary alcohol having from one to six carbon atoms the lower alkanol may include one or more of methanol ethanol denatured spirit n propanol isopropanol isobutanol n butanol and t butanol in particular the lower alkanol may include methanol and ethanol mixtures of all of these solvents are also contemplated the base includes alkali metal hydroxides amides alkoxides and alkali metals the alkali metal hydroxides include any hydroxide including for example lithium hydroxide sodium hydroxide and potassium hydroxide the product may be isolated from the solution by a technique which includes for example filtration filtration under vacuum decantation and centrifugation the product may be further or additionally dried to achieve the desired moisture values for example the product may be further or additionally dried in a tray drier dried under vacuum and or in a fluid bed drier the inventors have also developed a process for the preparation of substantially pure fexofenadine or a salt thereof by treating the fexofenadine containing corresponding keto analog as an impurity with a base adding reducing agent and isolating the substantially pure fexofenadine or a salt thereof having keto analog less than 0 05 as determined by reverse phase u2014 hplc the inventors have also developed a process for the preparation of highly pure fexofenadine or a salt thereof by treating fexofenadine containing corresponding meta isomer as an impurity with a base adding acid and isolating the highly pure fexofenadine or a salt thereof having keto analog and meta isomer each less than 0 05 as determined by reverse phase u2014 hplc the highly pure fexofenadine or a salt thereof thus obtained contains less than 0 1 of.