Development of a method to evaluate the effects of external environments on drug stability in nails using micro ‐segmental analysis

An evaluation method using micro-segmental analysis (MSA) of a single nail was developed to examine the effects of external environments on drug stability in nails. MSA is indispensable for examining various experimental conditions and maintaining the original nail shapes from a limited number of reference nail samples. AbstractNails can be used as an alternative to hair for examining past drug use. However, daily hand-and-nail care can eliminate the internal drugs. Therefore, we developed an evaluation method to examine the effects of the external environment on drug stability in nails using micro-segmental analysis. First, reference nails containing drugs were prepared by collecting fingernails from participants who had consumed hay-fever medicines continuously for 4  months. Next, the entire free edge of a reference nail was cut into halves at the centerline; one side was stored as an untreated block, and the other was treated with various hand/nail care products. Both nail blocks were washed and segmented at 0.5-mm intervals in the width direction. Each segme nt in the extraction solution was crushed with stainless-steel beads, sonicated, and soaked in the solution for 24 h. The analytes in extracts were quantified by LC–MS/MS, and the drug concentrations between the treated and untreated blocks were compared. The drug concentrations decreased slight ly in nails treated with manicure and gel-nail products. The analytes in nails tended to be lower in water-rich produc...
Source: Drug Testing and Analysis - Category: Drugs & Pharmacology Authors: Tags: RESEARCH ARTICLE Source Type: research