The quantitative analysis of tizanidine hydrochloride in both pharmaceutical dosage form and bulk medication has been developed and validated using an easy, affordable, quick, and unique isocratic HPLC approach. Tizanidine hydrochloride was separated isocratically using Waters symmetry C18 ODS as the stationary phase (250×4.6 mm, 5μm particle size), a flow rate of 1.0 ml/min, and a UV detector to track the eluate at 230 nm. The drug and its degradation products could be separated using the mobile phase, which was made up of acetonitrile: phosphate buffer (20:80 v/v) and pH-adjusted to 3.0 by ortho-phosphoric acid. Linearity, accuracy (recovery), precision, specificity, and robustness of the approach were all validated. For the range of 4-80 μg/ml, the linearity of the technique was satisfactory (correlation coefficient 0.999). Between 100.4 to 101.3% of the tizanidine hydrochloride was recovered from the medicinal dosage form. In order to analyze the samples, tizanidine hydrochloride was put under stress conditions, including hydrolysis (acid, base), oxidation, photolysis, and heat degradation. The tizanidine hydrochloride forced degradation study demonstrated that it decomposed under minimal conditions. Under the other stress scenarios examined, the medication remained steady. It was discovered that tizanidine hydrochloride was significantly more stable in its solid state than in its solution condition. The breakdown products were clearly distinguishable from the primary peak. The validation method may be useful for routine analysis of tizanidine hydrochloride as bulk drug, in respective dosage forms, for dissolution studies, and as a stability indicating assay method in pharmaceutical laboratories and industries because the forced degradation study proves the method's stability indicating power.
 Keywords: RP-HPLC, Tizanidine hydrochloride, Forced degradation, Method validated