Comparative Study on the Adequacy of Information and Dissolution Test between Original and Generic Drugs (I), Glibenclamide and Gliclazide / 医薬品情報学

  Generic drugs have received much attention especially from an economic point of view.  In Japan, the form of medical prescriptions has been revised twice in recent two years to disseminate generic drugs in recent two years.  The pharmacists are irresistibly required the detail knowledge of various generic drugs.  However, sufficient information on generic drugs has not always been provided in comparison with the original drugs.  This study intends to reveal such problems with the generic drugs.  Glibenclamide and gliclazide were selected as the model drugs for this study because these two drugs are often taken together with supplements.  Two approaches were used to compare the original drug and the corresponding generic drugs.  The first approach concerns the amount of information as well as the quality of the information that is provided from manufacturers.  The second approach concerns the physicochemical properties, dissolution test and hardness test.  Regarding the pharmacokinetic information in the package insert of glibenclamide, six generic drugs among eleven samples provided sufficient information while four samples seemed insufficient.  As for gliclazide, three samples among eight did not provide AUC and the time dependence of the blood concentration curve.  The results of the dissolution test revealed that all generic drugs satisfied most of the equivalence to the original drug except for one generic glibenclamide.  On the other hand, different behaviors in the swelling property and the time required to completely disperse were observed.  Two samples for glibenclamide and four samples for gliclazide required a fairly long time to completely disperse.  Irregular and significant variations were observed in the hardness test.  The difference in the dissolution process and hardness test suggested the different drug formulations among manufacturers.

A Computational Tongue Model and its Clinical Application / Oral Science International

The tongue possesses a complex muscular structure, and its motor functions are also intricate. Therefore, it would be beneficial to use a computational physiological model of the tongue to examine its vital functions in normal and pathological conditions. Thus far, the studies of tongue models have focused on symmetric movements for normal speech. For clinical purposes, it is necessary to develop a physiological model to deal with daily vital activities such as mastication and swallowing. To do so, we constructed a full 3D physiological model of the tongue based on MRI data from a normal subject, and verified the basic functions of the model based on anatomic and physiological knowledge. In this study, the model was applied to clinical issues: prediction and verification of the changes in movements of the tongue with a tumor before and after partial glossectomy, respectively. Tongue protrusion and lateral bending motion were examined for the prediction and verification. The simulation results were consistent with the observations for a patient with a tumor in the tongue. Comparisons of the simulation and observation in the clinical case showed that the model could predict potential effects of the glossectomy on the tongue movements. It is suggested that the model is a useful tool for pre-operative planning of glossectomy.

Perception of Hypernasality and its Physical Correlates / Oral Science International

To clarify the relationship between the perceptual diagnoses of hypernasality and its physical correlates, we conducted three experiments using the Japanese vowel /i/. We performed a spectral analysis of hypernasality on five cleft palate patients and six velum resection patients to investigate the spectral features related to hypernasality (experiment 1). Psychoacoustic experiments were conducted using various spectrally modified vowels to investigate the relationships between the spectral features and auditory perceptions of hypernasality (experiment 2). We analyzed the estimated spectral envelopes using an articulatory speech synthesis model to clarify the relationship between the spectral features and the velopharyngeal opening (experiment 3). Experiments 1 and 2 suggested four spectral features as the characteristics of hypernasality: (1) broadening of the F1 bandwidth, (2) an additional peak at around 1 kHz [P1], (3)^* a decrease in the magnitude of F2, and (4)^* a dip between F2 and F3 [D2]. In particular, the simultaneous modification of the decrease in the magnitudes of F2 and D2 is a very important cue for the auditory perception of hypernasality. Experiment 3 showed that the dips caused by nasal coupling resulted in the spectral modifications. In addition, the dip regions appeared to spread from the low-frequency region (around F1) to the high-frequency region (above F2), as the velopharyngeal opening enlarged. This suggests that the decrease in the magnitude of F2 and the dip between F2 and F3 [D2] are related to excessive acoustic coupling of the nasal cavity.^* New findings.