Maximal intestinal absorption of digoxin, and its relation to steady state plasma concentration.
(17/1213)
In a group of 8 volunteers, peak plasma digoxin concentrations and areas under 80-hour plasma concentration curves were significantly greater after 1 mg digoxin in paediatric elixir than after 4 0,25 mg tablets. Mean cumulative urinary excretion of digoxin over 12 days was 46.4 per cent after tablets, 53.6 per cent after elixir, and 70.8 per cent after intravenous injection. Mean percentage absorption was estimated to be 63 per cent from tablets and 75 per cent from elixir, but considerable between-subject variation was noted. Individual estimates of percentage absorption were significantly correlated with plasma concentrations in the steady state. Computer programmes to relate steady state plasma concentration to oral digoxin dosage take no account of absorptive capacity, are limited to gross approximations, and cannot replace determination of plasma concentration to assess the degree of digitalization. (+info)
Winter illness and vitamin C: the effect of relatively low doses.
(18/1213)
After their random -llocation to one of three treatment aroups, 622 volunteers received either vitamin C or placebo in a maintenance dose of 500 mg once weekly and a therapeutic dose of 1500 mg daily on the 1st day and 1000 mg on the next 4 days of any illness. Two forms of vitamin C were employed: a sustained-release capsule containing ascorbic acid and a regular tabet containing a mixture of sodium and calcium ascorbate. In the 448 subjects who completed an average of 15 weeks in the study of total of 635 episodes of illness were recroded. Respiratory symptoms were recorded on at least 1 day in 92 per cent of these episodes. There were no consistent or significant differences in the sickness experience of the subjects receiving the sustained-release vitamin capsules compared to those receiving the vitamin tablets, but subjects in both vitamin groups experienced less severe illness than subjects in the placebo group, with approximately 25 per cent fewer days spent indoors because of the illness (P smaller than 0.05). These results are compatible with the belief that supplementary vitamin C can reduce the burden of winter illness, but the intake need not be as high as has sometimes been claimed. (+info)
Application of infrared spectrophotometry to the identification of inorganic substances in dosage forms of Antacida group.
(19/1213)
Powdered tablets from the Antacida group: Alusal, Milk of Magnesia, Alumag, Maalox, Magnosil, Alugastrin, Malugastrin, Rennie, and components deciding about their antiacidity like Al(OH)3, Mg(OH)2, Mg2Si3O8, NaAl(OH)2CO3, MgAl(OH)(SO4)2, CaCO3, MgCO3, were subjected to infrared spectrophotometric investigations. It was found that infrared spectra of each pharmaceutical compound are different and show a series of characteristic maxima, by which they can be identified with in the spectral range of 4000 cm-1-200 cm-1. Comparison of infrared spectra of finished products with spectra of their components it was showed that the application of infrared spectrophotometry methods enabled us to prove the presence of particular compounds used in formulations. Tablet mass and odorizing agents do not cause significant changes in spectra of the tablets studied, preparations from the Antacida group. (+info)
A bioequivalence study of two brands of glipizide tablets.
(20/1213)
In this open, randomized, two way crossover, bioequivalence study, two 5 mg tablet preparations of glipizide (Glipizyd tabl. 5 mg, Tarchominskie Zaklady Farmaceutyczne POLFA S.A., and Glibenese tabl. 5 mg, Pfizer), were compared in 24 healthy male volunteers. Pharmacokinetic variables (mean maximum plasma concentration, mean time to reach maximum plasma concentration, and the mean area under the plasma concentration-time curve) were not statistically significantly different for the two formulations. It can be concluded that the two tablet preparations of glipizide are likely to be bioequivalent. (+info)
Bioavailability and dissolution of different formulations of oxytetracycline preparations.
(21/1213)
1 The concentration of oxytetracycline in plasma was studied by microbiological assay after oral administration of five different preparations of the antibiotic. None of these preparations had been studied previously. 2 There was a statistically significant correlation between the time required for 50% dissolution at pH 2 and biological availability, as assessed by the peak plasma level or the area under the plasma concentration-time curve. 3 The mean bioavailability of oxytetracycline was greatest with preparations of the hydrochloride, and with film-coated tablets of the dihydrate. In contrast, sugar-coated tablets of oxytetracycline dihydrate were associated with poorer dissolution characteristics and reduced biological availability. (+info)
Initial potency of lansoprazole and omeprazole tablets on pentagastrin-stimulated gastric acid secretion-a placebo-controlled study in healthy volunteers.
(22/1213)
BACKGROUND: The new tablet formulation of omeprazole (Losec MUPS), is thought to have a stronger acid inhibition than the previously marketed capsules. METHODS: The effects of the proton pump inhibitors lansoprazole and omeprazole tablets on pentagastrin-stimulated acid secretion were compared in Helicobacter pylori-negative healthy male volunteers (n=12). The study was placebo-controlled, crossover matched and double-blind for lansoprazole (Agopton) and placebo, and single-blind for omeprazole tablets. Gastric acid response to sub-maximal pentagastrin-stimulation (0.6 microg. h/kg b.w.) was determined from 12.5 to 14.5 h after the first and second dose of the test drugs. RESULTS: Lansoprazole 15 mg and 30 mg as well as omeprazole 20 mg tablets caused a marked decrease in gastric acid secretion, showing equipotency for 15 mg lansoprazole and 20 mg omeprazole tablets. Their efficacy, however, was lower than 30 mg lansoprazole. In addition, the inter-individual variation after omeprazole tablets was higher than following lansoprazole. Neither 7.5 mg lansoprazole nor 10 mg omeprazole tablets were clearly different from placebo on the first 2 days. The drugs were well-tolerated. No clinically relevant influence was found on either laboratory screen or cardiovascular parameters. CONCLUSION: Lansoprazole 15-30 mg shows a stronger acid inhibition and a lower inter-individual variability than the new omeprazole 20 mg tablets on days 1 and 2 of dosing. (+info)
Single daily dose of allopurinol.
(23/1213)
Allopurinol was administered to seven patients with gout to compare the effects of three different methods of administration. Allopurinol 100 mg given three times daily. Allopurinol given once daily as three 100 mg tablets. Allopurinol given once daily as a single 300 mg tablet. Allopurinol as a single dose in the morning gave as sustained control of plasma levels as did divided administration. (+info)
Bioavailability of praziquantel increases with concomitant administration of food.
(24/1213)
In the present study we found that after a single oral dose of 1,800 mg of praziquantel, following a high-lipid diet and a high-carbohydrate diet, the maximum levels in plasma increased 243 and 515% and the area under the plasma concentration curve from 0 to 8 h increased 180 and 271%, respectively. (+info)