Applicability of refractometry for fast routine checking of hospital preparations

Development of mucoadhesive films with high polaprezinc content for oral mucositis: A study on formulation and near-infrared spectroscopy-based quality control

Polaprezinc (PLZ) has drawn attention to its potential to prevent oral mucositis caused by chemotherapy and radiotherapy. PLZ-containing lozenges have been developed in previous reports; however, for patients with mucositis, taking them may be challenging because of pain. Therefore, this study aimed to develop a mucoadhesive film containing the same amount (18.75 mg) of PLZ as a lozenge as a new dosage form to replace lozenges and evaluate its characteristics. First, various films were created using solvent casting to screen polymers with high PLZ content. Thus, hydroxypropyl cellulose (HPC) was selected; however, film curvature and reduced flexibility necessitated formulation optimization. The optimized films exhibited excellent content uniformity, stability, and mucoadhesive properties, with no significant changes in the drug content after storage. Furthermore, the possibility of using portable near-infrared spectroscopy (Micro NIR™) for the quality control of PLZ films was investigated. Multivariate analysis revealed that the Micro NIR calibration model predicted drug concentrations comparable to those measured by high-performance liquid chromatography. These results suggest that a mucoadhesive film with high PLZ content has been developed and that efficient quality control is possible using Micro NIR™.

Application of Quantitative NMR Spectroscopy to the Quality Evaluation of Diclofenac Gargles as Hospital Preparations

Hospital preparations are frequently prepared in Japanese hospitals when ready-made formulations to meet patients' needs are unavailable. Although the quality of hospital preparations have to be ensured for efficacy and safety, such quality evaluation tends to be insufficient mainly due to lack of manpower and experimental environments in hospitals. In this paper, we investigated the applicability of quantitative (q)NMR spectroscopy to the quality control of diclofenac gargles as examples of hospital preparations, as it has various merits for the quantitative analysis of mixtures in solutions. Diclofenac gargles are composed of diclofenac, tranexamic acid, and lidocaine, and are used for the pain relief of stomatitis induced by cancer chemotherapy. Aliquots of the gargles, which were prepared five times, were mixed with dimethylsulfone as an internal standard, followed by qNMR measurements. Water signal suppression was achieved using a pulse program, water suppression enhanced through T₁ effects, because the pulse program was superior to other ones such as presaturation and one-dimensional nuclear Overhauser effect spectroscopy in terms of quantitativeness. Concentrations of the three medicinal ingredients were simultaneously determined based on the signals selected by considering the spectral separation and the quantitativeness. Consequently, the gargles were found to be prepared with constant quality, and were stable at room temperature for at least four weeks. qNMR is considered to be potentially useful for the quality control of various hospital preparations because of minimal sample pretreatments, lack of need of calibration curves, and its comprehensive detection abilities.

Diffractive refractometer for liquid characterization and transient processes monitoring

A simple refractometer using a reflective diffraction grating immersed in the test liquid is developed and its performance is studied. Due to the dependence of the light wavelength on the refractive index, determining the angle of the diffracted beam provides the refractive index of the liquid. The glass cell containing the test liquid is cylindrical, and the grating plane is parallel to the cylinder symmetry axis. The light beam normally impinges on the cell front wall and reaches the center of the grating so that the diffracted beam leaves the cell without being deviated by refraction. It is demonstrated that this characteristic of the optical setup minimizes important error sources due to undesired beam deviations and enables real-time refractive index measurement of liquids in transient processes. Moreover, the performances of the diffractive refractometer and of a commercial Abbe refractometer are compared in the measurement of the refractive indexes of aqueous NaCl solutions. A He-Ne laser at 632.8 nm is used as a light source, and the diffraction grating has 1200 lines/mm. Measurement precisions of the order of 8 × 10^-4 are achieved.