It is certainly a good idea to try topical application in combination with needling. But only in case of fibrotic scars such as you have. It is not suitable for acne scars because it inhibits collagen production and fibroblast proliferation.
Pirfenidone:"An orally active synthetic antifibrotic agent structurally similar to pyridine 2,4-dicarboxylate. Pirfenidone inhibits fibroblast, epidermal, platelet-derived, and transforming beta-1 growth factors, thereby slowing tumor cell proliferation. This agent also inhibits DNA synthesis and the production of mRNA for collagen types I and III, resulting in a reduction in radiation-induced fibrosis.
https://http://nci.nih.gov/drugdictionary?CdrID=38334 I think the topical formulation of Pirfenidone is called Kitoscell.
It claims to reduce the fibrous scars by inhibition of growth factor TGF-B1 production. Unfortunately, the medical trials of the product that worked on the same principle failed to reach the desirable effects. The product was called Juvista.
Phase III of their trials failed:
Professor Mark Ferguson, CEO Renovo, said: "We are extremely surprised and disappointed by the failure of Juvista to meet the Phase III trial primary and secondary endpoints."
https://http://www.renovo.com/en/news/juvista-eu-phase-3-trial-results Would you be willing to treat half of your scar with needling only and the other half with the Pirfenidone and needling and let us know the results?
In any case, let us know your results.
At the moment and as far as I am aware of, there are no credible products for the prevention or treatment of dermal scarring.