紫外可见光谱法可用于对大量药物物质的过程进行定量分析。它是用于分析不同药用物质的最重要的技术之一。它包括测量紫外线或可见辐射的量。因此，当紫外线或可见光被溶液吸收时，就可以进行测量。有大量的药物可以以原材料的形式使用，也可以作为配方使用(Kemp & William, 1991)。制备了药物溶液，并测量了特定波长的吸光度。同样的一个例子是安定片的定量分析。将0.5%的H2SO4在甲醇中混合，在给定波长下，其值约为284 nm。用来测量比值或比值函数或强度的仪器称为紫外可见分光光度计。
而在定性分析中，利用紫外可见光谱法可以很容易地对有机化合物进行鉴别。另一方面，为了保证吸收辐射的分子数量，进行了定量分析。该技术的优点是简单、特异、适用于多种化合物。可以用来控制这个过程的基本定律是比尔定律和朗伯定律。根据这一定律，与溶液吸光度有关的过程与溶液中一些最重要的吸收物质的浓度和路径的长度有关。用于对吸收紫外辐射的化合物进行定性分析。兰伯特定律指出，相互平行的单色辐射光束的总强度值将呈指数下降(Nockemann et al.， 2005)。当光束通过厚度均匀的介质时，会发生这种衰减。
UV Visible spectroscopy can be used for the process of quantitative analysis of a large number of pharmaceutical substances. It is one of the most important techniques which is used for the purpose of analysis of the different pharmaceutical substances. It involves the process including the measurement of the amount of ultraviolet or the visible radiation. Thus measurement is done when ultraviolet or the visible radiation is absorbed in the solution. There are a large number of drugs which can be used either in the form of raw materials or used as a formulation (Kemp & William, 1991). The solution of the drugs is made and the measurement of absorbance at a specific wavelength is done. An example of the same is the quantitative analysis of the Diazepam tablet. This tablet can be analyzed by mixing 0.5 % of H2SO4 in methanol at a given wavelength having a value of around 284 nm. The instrument which is used for measurement of the ratio or the function of ratio or the intensity is known as the ultraviolet visible spectrophotometers.
While during the qualitative analysis, it can be easy to do the identification of the organic compounds with the help of UV Visible spectrometry. On the other hand the quantitative analysis is done in order to ensure the number of molecules which absorbs the radiation. The usefulness of this technique is that it is simple, specific and can be applicable to a large number of compounds.The fundamental law which can be used for governing this process is the Beer’s law and the Lambert’s law. According to this law, the process related to the absorbance for this solution is related to the concentration of some of the most important absorbing species which is there in the solution and the length of the path. It is used for the qualitative analysis of those compounds which absorbs the UV Radiation. Lambert’s law states that the overall value of intensity of a beam of a monochromatic radiation which is parallel to one another would decrease in an exponential manner (Nockemann et al., 2005). This decrease occurs when the beam passes through the medium which has a homogenous thickness.