Chemical stability of cyproheptadine hydrochloride in an oral liquid dosage form

The chemical stability of cyproheptadine hydrochloride in an oral liquid dosage form was studied by using a stability-indicating high-performnace liquid chromatographic assay method that was developed in our laboratory. The concentrations of the drug were directly related to peak heights, with an R value of 0.991. The percent relative standard deviation based on five injections was 1.6. The products of decomposition and excipients present in the dosage forms did not interfere with the developed assay method. The mixture was stable for at least 180 days when stored in amber-colored glass bottles at room temperature. the pH value of the mixture remained constant at 3.7 after 180 days of storage, and the physical appearance of the formulation did not change during the study period.