Just back from New York City today. I bought a bottle of HC-110 this morning at their superstore (they won't ship it), and now that I'm back home (in Pittsburgh) I'm noticing that there's some brown gunk in a bottom corner of this brands new bottle. It's dated 2016. There are no dents or leaks in the bottle, and it feels inflated like it hasn't been opened. The gunk doesn't move when I slosh the liquid around. Any ideas what this could be? The liquid is yellow like I would expect. Thanks.
