I agree with Robert Smith that it would be better to move to a 'web-site' format. I also want to suggest to include pictures about each topic and if you have them, maybe not pictures from the Internet, but real pictures of your patients. You already have some great quotes from mothers with arthritis and I think those quotes and pictures from real patients would be a valuable resource to show the most human side of the information you want to communicate, they would help readers to connect on an emotional level with the impact of your project.
I have a couple of questions: 1. How recyclable sachets are? taking into account that they may have residues of liquid products inside. I found this article http://www.independent.co.uk/news/business/news/unilever-plastic-sachets-recycle-stop-enter-ocean-creasolv-process-billions-cosmetics-food-products-a7728396.html so would your idea work with any kind of sachets or would they have to be like the ones mentioned in the article?
2. The balance that the shop owner retains is part of the actual price of the sachet or is it an additional amount you pay and then recover?
Here in Colombia, many people buy hygiene and cleaning products in sachets or small packages so I think your idea could be very successful here, especially in low and middle-class neighborhoods.
I wonder if you have already gathered some feedback from your users, the graphics that you have so far are very clear and I think they would be useful to start a conversation with consumers and merchants to know what they think about your idea.
I'm looking forward to seeing where your project is going in the future.