Polymeric drug delivery systems have overcome challenge due to their biodegradability, biocompatibility and anti-toxicity. PLLA is well known for its superior mechanical properties, biodegradability and biocompatibility. Plasticizers with better biodegradability and presumably lower environmental toxicity are being developed. Thus, the biodegradability of the plasticizer determines the biodegradability of the starch blend. Further advantages for methanol is its ready biodegradability and low toxicity. Both standards above outline procedures for testing and labelling biodegradability in aerobic composting conditions. Its lower molecular weight compared to many polymers aids in its biodegradability. Compared to aliphatic polyesters, Nylon 6 has poor biodegradability. Branched alkanes have a lower biodegradability than unbranched alkanes. Interest in environmental safety has raised concerns about biodegradability of aminopolycarboxylates such as EDTA. Different SIs are designed for specific scaling conditions and biodegradability properties. Other advantages are low ecotoxicity and good biodegradability. Environmentalists prefer silk to nylon because of health and biodegradability issues. PGA is often used in medical applications such as PGA sutures for its biodegradability. There is an important difference between biodegradability and biobased content.