[Physico-chemical studies on adsorptive properties of pharmaceutic aids used in pharmaceutical technology. II. Mechanism of adsorption of sulfonamides on Veegum].
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
We discuss here the effect of water-insoluble pharmaceutical aids on the nature of drug release from composite polymeric prodrugs synthesized by mechanochemical solid-state polymerization. Magnesium stearate (Mgst) and hydrogen castor oil (HCO) were used as water-insoluble pharmaceutical aids. Composite polymeric prodrugs were synthesized by the mechanochemical solid-state polymerization of a vinyl monomer of 5-fluorouracil (I) in the presence of Mgst or HCO. The molecular weight of the resulting polymeric prodrugs increased with increasing the content of Mgst or HCO. Prodrug hydrolysis was carried out in a heterogeneous system in phosphate buffer at pH 6.8 and 37 degrees C. The rate of drug release from the composite polymeric prodrug containing Mgst (Poly-Mgst) was faster than that from polymeric prodrug containing no pharmaceutical aids (Poly-Non), while hydrolysis of the composite polymeric prodrug containing HCO (Poly-HCO) was slower than Poly-Non. Scanning electron microscope (SEM) photos showed the surface of Poly-HCO was smoother than that of Poly-Non and Poly-Mgst. It was suggested that the slower drug release from Poly-HCO may be responsible for the smaller specific surface area than that of Poly-Non. It was also shown that the rate of drug release from the composite polymeric prodrugs decreases with increasing the content of Mgst or HCO. Hence, novel composite polymeric prodrugs with a variety of drug release rates can be prepared by mechanochemical solid-state polymerization in a totally dry process.
Although nicotine replacement therapy (NRT) has shown efficacy in randomized controlled trials, population effectiveness has appeared to diminish after it became available over the counter. The present study examined the population effectiveness of bupropion. It also examined whether population effectiveness of pharmaceutical-aid use in general (NRT, bupropion, or both) might be influenced by environmental factors: Having a smoke-free home (possible indication of motivation to quit) or no other smoker in the household. Data from the large population-based cross-sectional 1999 and 2002 California Tobacco Surveys were combined to improve statistical power for subgroup analyses of duration of abstinence following the most recent quit attempt in the past year. Moderate-to-heavy daily smokers (at least 15 cigarettes/day) a year prior to the survey (N = 2,640) were the main focus. A Cox proportional-hazards analysis suggested that bupropion was effective, perhaps even in the longer term. Further analyses identified significant interactions on abstinence duration between having a smoke-free home and any pharmaceutical-aid use (NRT, bupropion, or both), and between having a smoke-free home and no other smoker in the household. Although pharmaceutical aids may have had a slight short-term benefit if the home was not smoke free, they appeared particularly effective if the home was smoke free, both in the short and longer term. The California population experience supports the policy that programs subsidizing pharmaceutical aids to help smokers quit (particularly bupropion, if appropriate) should target highly motivated smokers who have already taken a behavioral action, such as implementing a smoke-free home.
We carried out the mechanochemical polymerization of methacryloyl derivatives of acetoaminophen and 5-fluorouracil in the presence of lactose. The reaction proceeded readily and the polymeric prodrugs were quantitatively produced. This method produces powdered polymeric prodrugs in which fine particles of lactose are homogeneously dispersed, since the reaction proceeds quantitatively through a totally dry process. It is difficult to prepare such a powdered polymeric prodrug by conventional solution polymerization. The rate of drug release of polymeric prodrugs increases with increasing content of lactose, as is shown to be true of the specific surface of polymeric prodrugs. These results suggest that lactose is homogeneously dispersed in powdered polymeric prodrugs. The present method seems applicable to a wide variety of pharmaceutical aids. If one takes the physiochemical property of pharmaceutical aids into consideration, novel polymeric prodrugs with a variety of drug release rates can be synthesized simultaneously with mixing.
Explore the source record for details and available documents.
CONTEXT: Successful smoking cessation is a major public health goal. In controlled clinical trials, nicotine replacement therapy (NRT) and the antidepressant bupropion have been shown to significantly increase cessation rates only for moderate to heavy smokers (> or = 15 cigarettes/d). Nicotine replacement therapy is heavily promoted to the general population by both the pharmaceutical industry and tobacco control advocates. OBJECTIVE: To examine trends in smoking cessation, pharmaceutical cessation aid use, and success in cessation in the general California population. DESIGN, SETTING, AND PARTICIPANTS: The large population-based California Tobacco Surveys of 1992, 1996, and 1999, including 5247 (71.3% response rate), 9725 (72.9% response rate), and 6412 (68.4% response rate) respondents, respectively. MAIN OUTCOME MEASURES: Rates of cessation attempts (> or = 1 day) among smokers in the last year, use of pharmaceutical aids (mostly over-the-counter products since 1996), and cessation success. RESULTS: Between 1992 and 1999, cessation attempts among California smokers increased 61.4% (from 38.1% to 61.5%), and NRT use among quitters increased 50.5% (from 9.3% to 14.0%). A total of 17.2% of quitters used NRT, an antidepressant, or both as an aid to cessation in 1999. In 1996 and 1999, the median duration of aid use (14 days) was much less than recommended, and only about 20% of users had adjuvant one-on-one or group behavioral counseling. Use of NRT increased short-term cessation success in moderate to heavy smokers in each survey year. However, a long-term cessation advantage was only observed before NRT became widely available over-the-counter (August 1996). In 1999, no advantage for pharmaceutical aid users was observed in either the short or long term for the nearly 60% of California smokers classified as light smokers (<15 cigarettes/d). CONCLUSION: Since becoming available over the counter, NRT appears no longer effective in increasing long-term successful cessation in California smokers.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
With a view to expanding the application of a drug delivery system (DDS) preparation using plasma-irradiated pharmaceutical aids for various dosage forms, we studied the theophylline release property from plasma-irradiate polymer-coated granules, the polymers of which differ in the plasma irradiation effect. We used a new type of rotational plasma-irradiation reactor to perform plasma-irradiation uniformly on the surface of polymer-coated granules based on scanning electron microscope (SEM) observation. It was shown that an increase in theophylline release rate with an increase in plasma duration was observed in all polymer-coated granules, although the factors of such release properties vary with the polymers, as evidenced by the SEM observations. Such results provided the criteria for selecting polymer structures for granule coating. Thus, the present method for the control of drug release is considered principally applicable not only to polymer-coated granules but also to various drug forms under consideration of the above criteria.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
AIMS: Bioavailability of orally administered drugs depends on several factors including active excretion, e.g. by P-glycoprotein (PGP), and presystemic metabolism, e.g. by cytochrome P450 3A (CYP3A), in both gastrointestinal tract and liver. Many drugs including saquinavir are substrates of both PGP and CYP3A. It was the aim of this study to test whether the extremely low bioavailability of saquinavir can be increased dose-dependently in vivo by cremophor EL, an 'inactive' pharmaceutic aid known to inhibit PGP in vitro. METHODS: In a randomized, placebo-controlled, double-blind, four phase cross-over design single doses of oral saquinavir (Invirase, 600 mg, without food) were administered with increasing single doses of oral cremophor EL (up to 5000 mg) to eight healthy, male individuals. Saquinavir plasma concentrations were determined by LC/MS/MS up to 48 h after intake. Main outcome measures were area under the plasma concentration time curve (AUC), peak concentration (Cmax), time to reach Cmax (tmax) and terminal elimination half-life (t(1/2)). RESULTS: Cremophor EL dose-dependently increased Cmax, AUC(0,4 h), and AUC(0,infinity) of saquinavir. As compared with placebo, the increment observed after 5000 mg cremophor EL was 13-fold for both Cmax and AUC(0,4 h) and 5-fold for AUC(0,infinity). The terminal half-life and the time to reach Cmax (tmax) were unchanged. CONCLUSIONS: Cremophor EL increased the systemic availability of saquinavir without affecting its elimination suggesting that cremophor EL is not devoid of pharmacological action and acts as a modulator of the absorption process, probably by inhibiting intestinal PGP.