Infrared spectroscopy methods were used for attain the knowledge about stability of solid form of ranitidine hydrochloride (crystalline and tablets) during exposition on light. In a simple way and relatively short time the quantity of the changes on the surface of medicinal substances were estimated. Therefore, proper selection of the analytical method was extremely important aspect of this work. The effects of photochemical degradation of ranitidine hydrochloride and pharmaceutical products exposed to UVB radiation were recorded basing on the infrared spectroscopy using the infrared technique of transmission (FTIR) and reflection (ATR-FTIR). The usefulness of the ATR-FTIR technique to detect significant changes in generic pharmaceutical products with ranitidine hydrochloride caused by absorption of radiation was proven.