The aims of this study were to measure the physicochemical properties of miconazole nitrate (MCZ : a brand-name (MCZ-A) and three generic (MCZ-B, -C, and -D)) creams, to conduct human sensory testing of those creams. The flattening, viscoelasticity, and water content of each cream were measured and each cream was subjected to near-infrared (NIR) absorption spectroscopy and sensory testing. The yield value was calculated based on measured flattening and was 734.8 dynes/cm2 for MCZ-A, 1198.9 dynes/cm2 for MCZ-B, 461.3 dynes/cm2 for MCZ-C, and 3112.3 dynes/cm2 for MCZ-D. Measurement of viscoelasticity and viscosity revealed that MCZ-C had a smaller tanδ than the other 3 creams at 25ºC. NIR absorption spectroscopy revealed that MCZ-A had the highest absorption peak due to hydroxyl groups, followed by MCZ-C, -B, and then -D. Measurement of water content revealed that MCZ-A had a water content of 65.9%, MCZ-B, -C, and -D had a water content of around 56.3%. Human sensory testing revealed differences between MCZ-A and MCZ-C and between MCZ-B and MCZ-D in terms of spreadability and feel. These findings indicate that differences in water and oil content and emulsification resulted in the creams having different physical properties, such as flattening, internal structure, and dynamic viscoelasticity. NIR absorption spectroscopy, which allows non-destructive measurement of a sample’s physicochemical properties, and measurement of viscoelasticity and viscosity, which allows measurement of a sample’s dynamic viscoelasticity, revealed differences in the physical properties of creams.
Keywords: miconazole, spreadability, near-infrared, sensory test, physicochemical propertie
Providing safe and effective drugs to individual patients is an important responsibility of pharmacists. Medical costs borne by the Japanese public have soared over the past few years. Those costs need to be reduced, and use of generic drugs (generics) is recommended as one way to achieve that goal. Generics are cheaper than brand-name drugs but have the same quality. However, generics have gained little traction in Japan despite accounting for half of the drug market in the US and UK3). Testing to assess generics in Japan includes dissolution tests and bioequivalence tests. Only a few types of testing are used to assess some forms of preparations, there is a lack of information on the clinical efficacy and safety of these forms, and many experts feel that information on these forms is inadequate1)2). Types and ratios of additives are not necessarily the same for different external preparations, and many pharmacists question their quality4). In addition, information differences in the additives, method of manufacture, and properties of each preparation must be gathered when preparations are used even if they...