Hospital formulation has several advantages, including the flexibility of customization as per the disease state or the patients’ precise requirements. However, compared with commercial formulations, hospital formulations are usually not under the same level of quality check. In the present study, we tested mixed powder formulations prepared in a hospital pharmacy using Raman spectroscopy to investigate the feasibility of applying Raman spectroscopy as a quality-control tool of hospital formulations. For this purpose, we first established a numerical evaluation method to determine the uniformity of a powder mixture using Raman chemical imaging data with atropine sulfate/lactose mixture samples and revealed that the mixing uniformity correlated to the experience level of the pharmacist. Next, we developed a content quantification method in a one-dose packaged powder formulation by measuring the Raman spectra from the outside of the package. Because this method allows for quantification of the components inside the package in a non-destructive and non-contact manner, it can be applied for content confirmation after one-dose packaging. Using this method, the content uniformity of the mixed powder formulation in the one-dose package was compared between the formulations prepared by the pharmacists and those prepared by a pharmacy robot. Our study indicates the possibility of applying Raman spectroscopy as a quality-control tool of hospital formulations. Studies on further applications of Raman spectroscopy in the field of clinical pharmacology are expected.
Forty-four brands of transdermal patches for twelve kinds of active pharmaceutical ingredients (APIs) are available in Japan as of April 30, 2018. Although approximately one-third of the corresponding pharmaceutical interview forms lack information on how to evaluate the adhesive properties of the patches, the peel test, probe tack test, or inclined ball tack test have generally been adopted. This means that it might be difficult to simply compare the adhesive properties among the patches because the testing methods are not unified in some cases. In this study, measurements of the adhesive properties of 38 transdermal patches of ten different APIs were performed using several unified testing methods (180˚ peel test, 90˚ peel test, self-adhesion test, and probe tack test) under unified experimental conditions. The adhesive properties were found to be quite different among the patches, even for the same API, dose, and size. For example, the ratios of the maximum to minimum measured values of tack and 180˚ peel strength for tulobuterol patches were 5 and 29, respectively. In the case of generic products for which the bioequivalence to a brand-name product is assured, the variation in adhesive properties can extend the range of choices for patients, which is advantageous. Providing information to medical experts on adhesive properties through, for example, pharmaceutical interview forms and package inserts, is considered to be useful for helping patients to make better choices.