Maybe the big drug retailers (CVS/Walgreen/Walmart) could be interested in either owning or partnering with generic makers, as they can derive secondary benefits such as reputation/traffic even if a particular drug is temporarily unprofitable. They could also attempt "premium" generics like what Costco did with the Kirkland brand. You need a player that can benefit in other ways to prevent someone from gaining a monopoly through price manipulation.
Not familiar with the industry, but I don't think the problem can be solved this way (at least in the short term). Simply by the distribution of drugs/prices, there seems to be a very large number of low cost drugs susceptible to this tactic. There's ample space for them to pick a drug now and then and put abusive prices all of a sudden, while lowering the price as soon as competition threatens to move in. Additionally, the costs of reverse engineering a drug are high enough to make this kind of competition very hard. I see no other way than some regulation to at least force some hysteresis or stability on the prices.