There are also improved or modern baby feeding bottles out in the market. One example is Dr. Brown's Natural Flow Wide Neck Newborn Feeding Set BPA Free.
Furthermore, there are disposable BABY BOTTLES that can be used during travel. Formula or breast milk is poured into a disposable plastic pouch and is placed inside a holder called nurser. This also reduces air bubbles in the sense that the pouch collapses as the baby consumes the milk.
My baby uses Avent and we just change the teats as she grew older. As a newborn, we used PhilipsAVENT BPA-Free Newborn Nipple
There are lots of choices to choose from when it comes to plastic baby bottles, may it be for travel or regular use. Mothers can window shop and compare prices and see what's best for her baby and her budget.
Refrences: babycenter.com