Microwave heating temperatures and pharmaceutical powder characteristics

Abstract Temperature is an important factor that has a significant influence on the physical and chemical characteristics of the dried materials, mainly in the pharmaceutical solid powders. Pharmaceutical solids can be dried using different conventional drying techniques. However, in the present work, the technique of microwave irradiation was used to dry the moisturized formulation of naproxen-sodium drug. The exploitation of the microwave irradiation energy in the pharmaceutical field is limited, and the available information about the interaction between the electromagnetic radiations and the pharmaceutical material is still scarce. Therefore, this work aimed to explore the effects of the microwave irradiation temperatures on the elimination of the moisture, the morphology, the crystalline structure, the size of the dried particles, and the chemical groups of the naproxen-sodium drug. In the present research, a formulation of the naproxen-sodium drug was prepared and wetted by a wet granulation process. The prepared wet granules were dried at different heating temperatures using microwave irradiation energy. Powder X-ray diffraction, Fourier-transform Infra-red spectroscopy, moisture analyzer, and scanning electron microscopy were used to characterize the non-moisturized drug powder (the reference powder), the wet granules, and the dried granules. The results of this study exhibited that the use of the high microwave irradiation drying temperatures was more effectual in the removal of the moisture from the formulated naproxen-sodium drug than that at the low temperatures. Even though there was no significant variation in the chemical structure of the dried granules, crystallinity, morphology and particle size were relatively reformed with the variation in the microwave heating temperatures.