Cefixime nanoparticles were prepared by anti-solvent precipitation with syringe pump (APSP) method. Two simple and sensitive spectrophotometric methods I and II for the analysis of cefixime nanoparticles in either pure form or their pharmaceutical formulations are described. Method I is based on the oxidation of the drug with ferric ion succeed by complex development reaction with 1, 10-phenanthroline (1, 10-PTL) to obtain orange-red colored chromogen shows λmax at 510 nm also the method II on the reaction between diazotized drug with diphenylamine (DPA) in neutral medium to yield a pink-colored product which has λmax at 512 nm. The products are unchanging for more than 10 and 4 hrs respectively. Common excipients used as additives in pharmaceutical dosage do not impede the proposed methods. Thus the proposed methods proved to be easy, low cost, and accurate, are highly reproducible and have been applied to a broad range of pharmaceutical preparations and the outcome compares favorably with those of the official method. Prepared nanoparticles samples showed a better outcome than bulk drug samples.