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. One set of embodiments provides a composition for topical delivery comprising ibuprofen and/or an ibuprofen salt, a nitric oxide donor, and optionally, a hostile biophysical environment. In some cases, 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.