Want to buy a gallon of skin care cream at a time? Okay, the bottles aren’t that big, but it’s true that Sam’s Club, the nation’s second-largest club chain — behind Costco — has partnered with skin care product maker Sophyto to offer dermatological-grade, all-natural formulas in an unprecedented merchandising system for the retailer. This month, 150 Sam’s Club stores nationwide began selling Sophyto, a two-year-old brand founded by Karen Sinclair Drake, who now lives in Nap...