Studying the effect of pH variation on the incorporation of the antipsychotic drug clozapine into dyed and non-dyed hair samples using micro-attenuated total reflection spectroscopy.

Antipsychotic drugs are among the mostly widely used medications and are usually taken for prolonged periods of time. Due to its accumulation and trapping of drugs, hair can provide a useful indication of long-term exposure. Of interest also is what if any changes in the structural components of hair occur as a result of the drug binding process. Micro-attenuated total reflection (ATR) spectroscopy is able to examine the structural changes of hair samples by the application of sufficient pressure and without microtoming the hair (A. Koçak and S. L. Berets, Appl. Spectrosc. 62, 803 (2008)). In this investigation, we examined changes resulting from exposure of dyed and undyed hair to external clozapine as a function of the pH of the exposing solution. Single samples from different individuals and in one case from different regions of the scalp from the same individual were analyzed. The results demonstrated that pH related differences exist between drug-exposed dyed and non-dyed samples.