import re
p = re.compile(ur'(.*\.com)\/[^\/]+(\/prod[^\_]*\/p\.prod).*', re.DOTALL | re.IGNORECASE)
test_str = u"http://w...content-available-to-author-only...n.com/Ippolita-18k-Gold-Rock-Candy-Mini-Single-Square-Pendant-Necklace/prod108010011/p.prod#.U75MVqY-PtS"
subst = ur"\1\2"
result = re.sub(p, subst, test_str)
print result
aW1wb3J0IHJlCnAgPSByZS5jb21waWxlKHVyJyguKlwuY29tKVwvW15cL10rKFwvcHJvZFteXF9dKlwvcFwucHJvZCkuKicsIHJlLkRPVEFMTCB8IHJlLklHTk9SRUNBU0UpCnRlc3Rfc3RyID0gdSJodHRwOi8vdy4uLmNvbnRlbnQtYXZhaWxhYmxlLXRvLWF1dGhvci1vbmx5Li4ubi5jb20vSXBwb2xpdGEtMThrLUdvbGQtUm9jay1DYW5keS1NaW5pLVNpbmdsZS1TcXVhcmUtUGVuZGFudC1OZWNrbGFjZS9wcm9kMTA4MDEwMDExL3AucHJvZCMuVTc1TVZxWS1QdFMiCnN1YnN0ID0gdXIiXDFcMiIKcmVzdWx0ID0gcmUuc3ViKHAsIHN1YnN0LCB0ZXN0X3N0cikKcHJpbnQgcmVzdWx0