The present invention generally relates to the transdermal delivery of various compositions. In some aspects, the transdermal delivery may be facilitated by the use of a hostile biophysical environment. The composition may be stabilized using a stabilization polymer such as xanthan gum, KELTROL ® BT and/or KELTROL ® RD; propylene glycol; and a polysorbate surfactant such as Polysorbate 20, which unexpectedly provides temperature stability to the composition, e.g., at elevated temperatures such as at least 40 °C (at least about 104 °F), as compared to compositions lacking one or more of these.