Celery (Apium graveolens L.) contains flavonoids, which are helpful for anti-inflammation. Celery will be extracted and made into a nanoparticle system, then formulated in a gel dosage form. Nanotechnology can improve drug bioavailability and the accurate release of active substances. Sodium alginate has a lot of functional groups that allow it to bind enough active ingredient molecules, and the positive ion charge will cross-link with the negative ion charge of calcium chloride (CaCl2). To obtain optimal concentrations of sodium alginate and CaCl2 to make celery nanoparticles and to obtain information on the physical characteristics of celery extract nanoparticles. Optimization of the celery extract nanoparticle formula using the simplex lattice design optimization method with the help of Design-Expert Software. optimal nanoparticle formula with a sodium alginate concentration of 0.600% and a CaCl2 concentration of 0.400%, a desirability value of 0.948, and a transmittance value of 99.8967. Then, samples with 1 mg/ml and 25 mg/ml were observed for particle size, and results were obtained at 1175 nm and 2682 nm, respectively.