A simple isocratic technique was developed for the analysis of nicotine hydrogen tartrate using high-performance liquid chromatography with UV detection. Nicotine was separared from its main degradation products (cotinine, nicotine-l'-oxide, nicotinic acid) on a special C₁₈ reverse-phase column. The quantitative analysis of nicotine was characterized with respect to specificity, linearity, accuracy and precision, and showed a good intra-day and inter-day precision and accurace (RSD < 2.5%). Nicotine concentration in solution, in a nasal spray formulation and in Sephadex microspheres (G25 and G50) was followed over a period of 5 mounths under different conditions of temperature and light. The study showed a slight loss of nicotine concentration (<5%) in solution and in spray after 5 months: solutions exposed to light displayed a pale yellow coloration. The nicotine concentration in the microsphere did not significantly vary. None of the above mentioned main degradation products of nicotine were detected in this stability study.