A Phase IIb/III Clinical Study to Evaluate the Efficacy and Safety of APC101 in Patients With Postherpetic Neuralgia.

APC101 is a film-forming, sustained-release, and metered-dose topical spray. This investigational product (IP) is formulated with 5% by weight of lidocaine and several excipients. APC101 offers several unique properties or advantages over the first line topical treatment of lidocaine patches, including: * Can be applied to the area above the neck (face and head). * Contact-free: eliminating pain when apply to the skin of PHN patients. * Suitable to apply to uneven skin of PHN patient. * Less adverse reactions such as skin rash and redness at the application sites. * Less systemic absorption compared with patch, which shows safer profile. * Can be administered twice daily as needed. * The only prescription spray product providing pain relief for PHN with clinical evidence. This is a Phase IIb/III, randomized, double-blind, placebo-controlled clinical study to evaluate the efficacy and safety of APC101 in patients with PHN.