I have been using a similar formulation to some relief from the biceps pain. It is NSAID (diclofenac sodium) and menthol formulation. I think that it provides a temporary distraction from the real pain because of menthol. I don't think that anything applied to skin can really reach the deep tissues. NSAID absorption from skin will help to some extent, however the amount of drug absorbed will be much less than oral administration.
Have any of you used the lidoderm patch? It does require a perscription and is pretty pricy. My copay was $50.00 for a box of 30, but I will tell you I couldn't wait to slap one one at night. It is patch about 4 x 6 that is infused with lidocaine. Within 20 minutes I felt relief. There is another gentleman on this site who has had multiple shoulder surgeries and he has had great luck with them. I also like Biofreeze, more of a distraction from pain, but whatever it takes when you are hurting.
I had tried a patch sample from the OS once before with no luck. I can guarantee my insurance wouldn't cover them. I was given an RX for pensaid last week and they denied that, which is why i have the voltaren now.