definiens: shall mean, on a country by country and Product by Product basis, the period from a Product Launch Date of each such Product in such country in the Territory until the date of ( i ) expiration of the last valid claim of a patent issued in such country included in the Patent Rights which claims such Product, or ( ii ) the tenth ( loth ) anniversary of the Product Launch Date, whichever the later, provided, however, that for the purpose of calculating Product Royalty Period, the Product Launch Date for Single Product and Steroid Combination Product shall occur only once each for Single Product and Steroid Combination Product . For the purpose of clarification, the Product Launch Date for Single Product and Steroid Combination Product shall be the date when first Single Product or Steroid Combination Product is marketed in each country regardless of subsequent commercial launches of different Single Product(s ) or Steroid Combination Product(s ) . In contrast, for purposes of clarification, a Product Launch Date shall occur for each Multiple API Combination Product containing a different API with the Compound which shall be the date when the first Multiple API Combination Product containing such API and the Compound is marketed in each country regardless of subsequent commercial launches of different Multiple API Combination Products containing the same API and the Compound