Some ortho-phthalates, including di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP), have been identified as reproductive and developmental toxicants in laboratory animals (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlFoster 2005; The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlHowdeshell et al. 2008). Similar effects have not been reported in animals exposed to diethyl phthalate (DEP); however, limited human studies have suggested a possible association between DEP exposure and male reproductive health outcomes (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlSwan 2008). Studies have shown widespread population exposure to background levels of phthalates (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlSilva et al. 2004). Of concern, particularly high exposure levels may result from orally ingested medicinal products containing phthalates as inactive ingredients. For example, increased urinary concentrations of phthalate metabolites were first reported for an individual taking a mesalamine product (Asacol; Warner Chilcott Pharmaceuticals Inc., Mason, OH) (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlHauser et al. 2004) and later confirmed for individuals taking mesalamine and other drug products (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlHernández-Díaz et al. 2009). High urinary concentrations of phthalate metabolites have also been identified in patients with cystic fibrosis who used pancreatic enzyme products (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlKeller et al. 2009). This has led to increased interest in identifying additional drug products that contain phthalates as inactive ingredients.
Inactive ingredients (excipients) are defined as “any component other than the active ingredient in a drug product” (FDA 2011). These various compounds may be used in drug formulations for a number of functions related to the preparation and stability of the physical dosage form or the delivery of active ingredients (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlRowe et al. 2009). Excipients used in specialized drug product formulations may permit a) localized availability of active medications in various sections of the gastrointestinal (GI) tract, b) controlled release of a medication over time, or c) through the skin. Phthalates, in combination with various polymers, may be used as plasticizers and film coating agents in orally ingested solid pharmaceutical dosage forms and in numerous types of modified-release drug delivery systems such as enteric-coated and delayed-release tablets, pelletized delayed-release capsules, enteric-coated capsules, and controlled-release transdermal films (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlAllen et al. 2005).
Several different phthalates are currently used as excipients in approved pharmaceutical formulations: diethyl phthalate (DEP), dibutyl phthalate (DBP), dimethyl phthalate (DMP), dioctylphthalate (DOP), hypromellose phthalate (HMP), cellulose acetate phthalate (CAP), polyvinyl acetate phthalate (PVAP), and polyethylene terphthalate (PET) [Food and Drug Administration (FDA) 2010b]. These compounds are not themselves technically “approved” for general use as excipients; rather, they are permitted to be included in their corresponding approved drug products, with maximum levels designated for each type of dosage form and route of administration (The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlOsterberg and See 2003; The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.Destroy user interface controlSteinberg and Silverstein 2003). The maximum amount of DBP used in specific FDA-approved drug products ranges from 1.70 mg for a delayed-action, enteric-coated tablet formulation to 11.18 mg for an extended-release capsule product. DEP has been approved at amounts ranging from 0.5 mg for an uncoated, chewable tablet to 16.8 mg for a delayed-action, enteric-coated capsule (FDA 2010b).