Background: Biodegradable polymers are fuelling the development of drug delivery systems due to their biocompatibility, biodegradability, and ease fabrication. Poly (lactic-co-glycolic acid) (PLGA) is one of such biodegradable polymer and is Food and Drug Administration (FDA) approved. Poly glycerol adipate-co-ω-pentadecalactone (PGA-co-PDL) is such a new polymer that has been developed and characterized in house laboratory to improve upon the physicochemical properties of PLGA. It was successfully formulated into nanocarriers. The study aims to evaluate the in-vitro cytotoxicity profile of PGA-co-PDL Nanoparticles (NPs) carriers in comparison to PLGA NPs for pulmonary drug delivery. Methods: NPs were formulated from PGA-co-PDL and PLGA by single emulsion using different (anionic and cationic) emulsifiers. The NPs were characterized for size and charge. In-vitro cytotoxicity was evaluated by Alamar Blue (AB), and Reactive Oxygen Species (ROS) assays using Calu-3 cells. Results: PGA-co-PDL NPs showed good toxicity profile in comparison to PLGA NPs. The anionic NPs were more compatible to the cationic NPs. Less ROS production was detected with the anionic NPs. Conclusion: PGA-co-PDL polymer was successfully formulated into NPs with a suitable size range for pulmonary drug delivery. The results showed a good toxicity profile of PGA-co-PDL NPs in comparison with the PLGA NPs. The anionic particles showed better compatibility confirming future suitability for pulmonary drug delivery.