Abstract 【Background】 Promoting the use of generic preparations is an important means to curtail increasing medical costs. However, anxiety regarding the quality of generic preparations inhibits their use. In this study, we compared the quality of brand name and generic theophylline extended-release tablets by examining their dissolution profiles. The purpose of this study was to determine which generic preparations the pharmacist should recommend as an alternative to the brand preparation, thereby contributing to patients’ safety. 【Methods】 The dissolution profile of theophylline from generic theophylline extended-release tablets was tested and compared to that of the brand preparation. Two or three lots per preparation of nine preparations were tested. Each tablet contained 100 mg theophylline. 【Results】 The dissolution profiles were grouped into four types based on their dissolution in water. Some tablets showed slight variance between lots. When assessing similarities between the dissolution profiles, in some cases we could not distinguish between the generic and the brand preparation found in the Orange Book. 【Conclusion】 When pharmacists select a generic preparation for a patient, it is important to consider the dissolution profile of the brand name preparation because dissolution profiles vary among tablets. Although theophylline extended-release tablets can be divided into groups based on the dissolution profile in the Orange Book, it seems that there are slight differences in dissolution profiles within the same group under different patient conditions. Pharmacists should consider the patient’s condition when changing from the brand preparation to a generic preparation.

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Pharmaceuticals and medical devices can interact with drugs by attachment and sorption onto transfusion tubes, filters, and other plastic products, making it challenging to ensure proper dosage. In particular, although the use of plastic products such as dentures and denture adhesives is widespread in the oral cavity, reports examining the interaction between these products and pharmaceuticals are lacking. The authors investigated whether these products interact with oral spray formulations, sublingual tablets, and orally disintegrating (OD) tablets. Aqueous solutions of 13 different drugs were exposed to an insoluble denture adhesive for 1 h, and the percentage drug adsorption was calculated by measuring the percentage of each drug remaining in solution using 1H-NMR. Following the exposure of each drug to the denture adhesive, nine drugs demonstrated 5% or less adsorption. In contrast, 20% and 45% of valsartan and irbesartan OD tablets, respectively, were adsorbed. Moreover, isosorbide dinitrate and nitroglycerine, both used sublingually, demonstrated 70% and 30% adsorption, respectively. The percentage absorption of each of these drugs was significantly higher than that of the control (P<0.05). Furthermore, the percentage adsorption of these four drugs correlated with the partition coefficient (P<0.05). These results suggested that the therapeutic effect of sublingual tablets and OD tablets, which are often retained in the mouth, could be potentially reduced in patients in the presence of denture adhesives owing to attachment and sorption. Further investigations are imperative to identify other drugs at risk of adsorption and altered efficacy.

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