I think that one of the challenges regarding plastic waste is that the biggest consumers of particularly small format plastic packaging in the world are in countries with limited waste management facilities. Thus any designs which reduce the amount of plastic in packaging such as in the travel/refill pouch are important.
The barrier stick plant based packaging is another really useful design solution to plastic waste. The UNEP has found that biodegradable plastics aren't the solution to marine litter (http://www.unep.org/asiapacific/biodegradable-plastics-are-not-answer-reducing-marine-litter-says-un). I think that whilst reducing packaging is of critical importance there is a need to also have packaging options which are truly biodegradable in any environment and has potential for use with other products means that this is an idea which can be implemented at scale.