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Apparatus for studying in vitro drug release from medicated chewing gums.

Kvist C, Andersson SB, Fors S, Wennergren B, Berglund J.

Pharmacia and Upjohn, Consumer Healthcare, Research and Development, P.O. Box 941, SE-251 09, Helsingborg, Sweden.

An apparatus for in vitro drug release testing of medicated chewing gums has been developed and is described in detail. The effects on the drug release when varying critical instrumental settings such as the chewing stroke frequency, the distance between the chewing surfaces, the twisting movements of these surfaces and the temperature of the test medium have been thoroughly investigated. It has been shown that the drug release can be tuned to obtain suitable drug release profiles for a number of products: Nicorette((R)) and Nicotinell((R)) (active substance nicotine), Travvell((R)) (dimenhydrinate), V6((R)) (xylitol) and an experimental formulation containing meclizine. The main usage of the present apparatus should be within quality control but the present study has also shown that it may be employed within development pharmaceutics since useful in vivo/in vitro relationships may be obtained due to the versatile settings of the critical instrumental parameters.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10518685&dopt=Abstract dimenhydrinate meclizine Antivert



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The use of non-prescription sleep products in the elderly.

Sproule BA, Busto UE, Buckle C, Herrmann N, Bowles S.

Psychopharmacology Research Program, Sunnybrook and Women's Health Sciences Centre, Toronto, Canada. sproule srcl.sunnybrook.utoronto.ca

While sleep disorders are common in the elderly, the use of non-prescription products for sleep in this population has not been fully evaluated. The objectives of this project were to assess the use, perceived effectiveness and toxicity of non-prescription sleep products in an ambulatory elderly population. METHODS: A self-administered 20-question survey was distributed to seniors, aged 60 years or more, during hospital or pharmacy visits. RESULTS: Of the total respondents (N=176, mean age 74+/-7 years, 59% female), 84 (48%) indicated that they had used one or more therapies for sleep within the past year. These included non-prescription products (50% of therapies), prescription products (17%) and non-drug activities such as walking or drinking milk (34%). For those individuals who had used a non-prescription product in the past year (N=47, 27% of total respondents), the most frequently used products were: dimenhydrinate (21%), acetaminophen (19%), diphenhydramine (15%), alcohol (13%) and herbal products (11%). Most took them at least 1 day per week (79%) and 32% took them daily. These products subjectively improved sleep latency (mean 32 vs 61 minutes, p<0.001), number of nocturnal awakenings (mean 2 vs 3 awakenings, p<0.001) and total hours of sleep (mean 6.6 vs 5.4 hours, p<0.001). Mild side-effects were reported by 35 respondents (75%), the most common being dry mouth (N=22) and daytime drowsiness (N=13). Respondents were taking an average of four (SD+/-3, range 0-10) other medications currently. CONCLUSIONS: Non-prescription products are widely used by this population of ambulatory elderly for sleep disturbances. Most of the products were not marketed for sleep; however, they were perceived to be efficacious with low toxicity. The potential for drug interaction is high. Further research is warranted to evaluate the safety and effectiveness of non-prescription sleep products in the elderly. Copyright 1999 John Wiley & Sons, Ltd.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10521884&dopt=Abstract dimenhydrinate meclizine Antivert



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Inhibition of human liver steroid sulfotransferase activities by drugs: a novel mechanism of drug toxicity?

Bamforth KJ, Dalgliesh K, Coughtrie MW.

Department of Biochemical Medicine, University of Dundee, Ninewells Hospital and Medical School, Scotland, UK.

The inhibition of steroid and phenol sulfotransferase activities in human liver cytosol by a wide range of commonly used drugs was studied. Dehydroepiandrosterone (DHEA) and estrone sulfotransferase activities were strongly inhibited by a number of compounds, with IC50 values ranging between 440 pM and 147 microM. For DHEA sulfotransferase, clomiphene, testosterone, danazol and spironolactone were the best inhibitors, with IC50 values less than 5 microM, whereas for estrone sulfotransferase cyclizine, ibuprofen, chlorpheniramine and dimenhydrinate resulted in the strongest inhibition, again with IC50 values of less than 5 microM. The xenobiotic substrate 1-naphthol was refractory to substantial inhibition, with the exception of clomiphene. The majority of the drugs which inhibited steroid ST activities strongly were either synthetic steroids, antisteroidals or were tertiary amine drugs such as tricyclic antidepressants and antihistamines, many of which exhibit adverse side effects manifesting particularly as sexual dysfunction and disruption of hormone action in clinical use. The importance of these findings for our understanding of the molecular basis of adverse drug reactions is discussed.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1397064&dopt=Abstract dimenhydrinate meclizine Antivert



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Studies on controlled release dimenhydrinate from matrix tablet formulations.

Genc L, Bilac H, Guler E.

Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Technology, Eskisehir, Turkey. lgenc andolu.edu.tr

In this study, controlled release dosage forms of dimenhydrinate were prepared with different polymers as MC, HEC, Carbopol 934, Eudragit RLPM and Eudragit NE 30 D at different concentrations (2.5-10%). Direct compression (DC) and wet granulation (WG) techniques were used to prepare the tablets. Magnesium stearate was the lubricant while starch gel was the binder. For the quality control of tablets prepared according to 11 different formulations, weight deviation, hardness, friability, diameter-height ratio, content uniformity of the active substance and in vitro dissolution techniques were performed. Dissolution rate of these tablets was controlled by USP XXII dissolution method and the profile of each tablet was plotted and only for F 5 was evaluated kinetically.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10748623&dopt=Abstract dimenhydrinate meclizine Antivert