Forced degradation study is the degradation of new drug substances and drug products in more severe conditions than accelerated conditions. Forced degradation study were conducted to demonstrate the specificity of stability-indicating methods, providing insight into degradation pathways and drug degradation products, assisting in the elucidation of degradation product structures, identifying degradation products that could be spontaneously generated during storage and use of drugs and to facilitate improvement in manufacturing process and formulation corresponding with accelerated stability studies. Statins, a class of lipid-lowering medications, are the most widely prescribed drugs and an example of an unstable drug. Statins are susceptible to hydrolysis in the presence of high temperatures and humidity. Therefore, the review discusses various studies of forced degradation studies in six statins drug (atorvastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin) to describe the drug's intrinsic stability thus it can assist the selection of formulations and packaging as well as proper storage conditions.

Drug stability is one of the most important criteria for producing safe, excellent and effective products. Some environmental factors that influence drug stability are light, temperature, and humidity. Simvastatin is a cholesterol-lowering drug that is known to be sensitive to high temperature and humidity. The purpose of this study is to analyze the effect of 6 months of real-time storage conditions on the stability of generic simvastatin tablets in public pharmacy facilities. This study used simulation method with 4 brands of simvastatin generic tablets with two different strengths (10 mg and 20 mg). In the process, the sample was conditioned in 6 different regions for 6 months. The results of temperature and humidity monitoring showed 2 locations at ≤ 25 ° C, 4 locations had a temperature of ≥ 25 °C and all locations had humidity > 65 %. The drug was evaluated for physical and chemical quality parameters at months 0, 3, and 6. After being stored for 6 months, the tablets showed a decrease in disintegration time and an increase in the friability, showing lack of durability. Similarly, there was a decrease in the content concentration in the tablets but fortunately the level was still within the accepted specification range (90 – 110 %). However, there was one tablet that did not meet the dissolution test requirements after the storage duration (Q ≤ 75 % at 30 minutes). The results of the stress test showed that simvastatin degraded in all conditions. This stress test confirmed the extreme instability of simvastatin.  Poor storage conditions can reduce the quality of generic simvastatin tablets, thus a well-controlled environment is vital in pharmacy facilities.