烟酰胺及其复配体系的稳定性研究

Study on the stability of niacinamide and its mixed system

以5%烟酰胺、5%烟酰胺+0.5%MSH、5%烟酰胺+1.0%MSH 3个体系为研究对象,以高效液相色谱法测定烟酰胺水解产生烟酸的含量为指标,考察pH值、温度以及光照等条件对体系稳定性的影响。结果表明,各考察条件对体系的影响顺序依次为45℃>循环(-15℃~48℃)≈37℃光照>5℃≈-10℃;pH值对烟酰胺水解有显著的影响,特别是高温条件下,且pH值越大影响越显著;MSH会促进烟酰胺水解,且随着MSH含量增加影响程度增加,同时,pH值越大,MSH对体系的影响越大,但MSH对体系的影响小于pH值。因此,无论是在烟酰胺体系还是在烟酰胺与MSH复配体系,都应严格控制体系的pH值在6.0左右,尽量不要超过6.5,且应保持低温及避免光照。

The effects of pH,temperature and light on the stability of 5%niacinamide,5%niacinamide+0.5%MSH,5%niacinamide+1.0%MSH were studied by HPLC to detect the hydrolysis product nicotinic acid.The results show that the influences of conditions on the systems are in the decreasing order:45℃>cycle(-15℃~48℃)≈37℃lighting>5℃≈-10℃.pH has significant effects on the hydrolysis of niacinamide,especially at high temperatures(The higher the pH is,the more significant the effect will be).MSH can promote the hydrolysis of niacinamide,and such influence will increase with the increase of MSH content.Moreover,such influence of MSH will be higher at higher pH values.However,the influence of MSH on the systems is less than that of pH.Therefore,in the niacinamide system or the niacinamide/MSH mixed system,to inhibit the hydrolysis of niacinamide,the pH value should be controlled at approximately 6.0 and not exceeding 6.5,and the system should be kept at low temperature and avoid light.