Intraocular tissues, sensitivity

Low-dose regimens frequently result in very low corticosteroid concentrations in body fluids (e.g., low pg/mL range in plasma). PK analysis that is often necessary to manage these therapies is hindered by the inadequate sensitivity by most established analytical methods. In addition, certain drug delivery strategies, such as inhalation or intraocular injection, result in systemic levels too low to be detected by current methods. Furthermore, administration of some corticosteroid prodrugs, such as these in the forms of acetates/propionate, often results in sustained, low concentrations in plasma. Therefore, a highly sensitive and selective analytical approach is necessary for cases in which sustained low concentration of corticosteroids may be present systemically or in tissues. 

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