PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Tablets”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 469 records · Page 26Linked to original sources

In vivo drug release from hydrophilic dextran tablets capable of forming polyion complex.

The aim of this comparative study was to investigate the in vivo drug release property of hydrophilic dextran tablets with or without swelling in the upper gastrointestinal tract (GIT) in humans. Two kinds of theophylline (TH) tablets were prepared by direct compression from a mixture of carboxymethyldextran and [2-(diethylamino)ethyl]dextran as a matrix capable of forming polyion complex (PIC-tablet), and a mixture of low and medium molecular weight hydroxypropylcellulose as a representative hydrophilic matrix (HPC-tablet). In these tablets, in vitro drug release behaviors and saliva TH level profiles after oral administration to humans were similar to each other, indicating equivalent AUC value. The tablets were then coated with Eudragit S100, enteric-coating polymer, by a dipping method in order to reveal drug release without full swelling in the upper GIT. Although the two enteric-coated tablets showed a similar in vitro release pattern, saliva level profiles were quite different as reflected in AUC values of 16.4 and 4.68 microg h/ml for enteric-coated PIC- and enteric-coated HPC-tablet, respectively. These results demonstrated that HPC-tablet could not release sufficiently without swelling in the upper GIT. In contrast, enteric-coated PIC-tablet showed an equivalent AUC value to PIC-tablet, indicating that TH was released well even in the lower GIT.

Administration, Oral↗

Floating hot-melt extruded tablets for gastroretentive controlled drug release system.

The purpose of this study was to investigate the influence of sodium bicarbonate on the physicochemical properties of controlled release hot-melt extruded (HME) tablets containing Eudragit RS PO and/or Eudragit E PO. Acetohydroxamic acid and chlorpheniramine maleate were used as model drugs. Sodium bicarbonate was incorporated into the tablet formulations and the drug release properties and buoyancy in media for HME tablets and directly compressed (DC) tablets were investigated. The HME tablets prepared from the powder blend containing both Eudragit RS PO and sodium bicarbonate exhibited sustained release properties and the tablets floated on the surface of the media for 24 h. The cross-sectional morphology of the HME tablets showed a porous structure since CO(2) gas was generated due to the thermal decomposition of sodium bicarbonate in the softened acrylic polymers at elevated temperature during the extrusion process. In contrast, all DC tablets prepared in this study showed no buoyancy and rapid drug release in the dissolution media. The drug release rate from floating HME tablets was controlled by both the incorporation of Eudragit E PO into the matrix tablet and the diameter of the die used in the extrusion equipment. The drug release profiles and buoyancy of the floating HME tablets were stable when stored at 40 degrees C/75%RH for 3 months.

Algorithms↗

Micronized ethylcellulose used for designing a directly compressed time-controlled disintegration tablet.

Ethylcellulose (EC) of varying particle sizes has been used as an outer coating layer to design a novel dry-coated tablet with time-controlled drug release. This dry-coated tablet, containing a core tablet of sodium diclofenac and an outer coating layer of EC, was prepared by direct compression. The drug release from dry-coated tablet exhibited an initial lag period that was dependent on the particle size of the EC powder, followed by a stage of rapid drug release. The smaller the EC particle size used the longer the lag time obtained, suggesting the particle size of EC powder could modulate the timing of drug release from such a dry-coated tablet. The period of the lag time for sodium diclofenac released from dry-coated tablets was correlated with the penetration distance of the solvent into dry-coated tablet by an in vitro dye penetration study. The densest packing of EC powders appeared on the upper and lower surfaces of dry-coated tablet after compression, resulting in a tight structure yielding a slower penetration of the solvent. Whereas loose packing of EC powders occurred in the middle of the lateral surface of dry-coated tablet, this loosely packed surface readily allowed solvent penetration and that finally caused the splitting of tablet shell into two halves in the dissolution medium. The results suggest that these dry-coated tablets prepared with different particle sizes of EC powder as an outer coating layer might offer a desirable release profile for drug delivery at the predetermined times and/or sites.

Cellulose↗

Transmucosal sustained-delivery of chlorpheniramine maleate in rabbits using a novel, natural mucoadhesive gum as an excipient in buccal tablets.

The objective of this study was to evaluate the gum from Hakea gibbosa (Hakea) as a sustained-release and mucoadhesive component in buccal tablets following their application to the buccal mucosa of rabbits. Flat-faced core tablets containing either 22 or 32 mg of Hakea and 40 or 25 mg of chlorpheniramine maleate (CPM) per tablet with either sodium bicarbonate or tartaric acid in a 1:1.5 molar ratio were formulated using a direct compression technique and were coated with Cutina(R) on all but one face. The resulting plasma CPM concentration versus time profiles were determined following buccal application of the tablets in rabbits. The strength of mucoadhesion of the tablets was also quantitated in terms of the force of detachment as a function of time. Following the application of the mucoadhesive buccal tablets, the following values for several pharmacokinetic parameters were obtained. The force of detachment for the mucoadhesive buccal tablets containing 22 mg of Hakea and either 25 and 40 mg CPM, and 32 mg Hakea and 40 mg CPM increased from 1.64+/-0.47 to 7.32+/-0.34 N, 1.67+/-0.30 to 7.21+/-0.36 N, and 2.93+/-0.73 to 7.92+/-0.60 N, respectively from 5 to 90 min following application to excised intestinal mucosa. Addition of either sodium bicarbonate or tartaric acid, as well as higher amounts of CPM, did not affect the mucoadhesive bond strength. These results demonstrate that the novel, natural gum, H. gibbosa, may not only be used to sustain the release of CPM from a unidirectional-release buccal tablet, but also demonstrate that the tablets are sufficiently mucoadhesive for clinical application. The mucoadhesive strength as measured by the force of detachment, can be modulated by altering the amount of Hakea in the tablet. The mucoadhesive buccal tablets evaluated represent an improved transbuccal delivery system for conventional drug substances.

Adhesives↗

Tabletting behaviour of pellets of a series of porosities--a comparisonbetween pellets of two different compositions.

The tabletting behaviour of pellets prepared from a 4:1 mixture of dicalcium phosphate dihydrate (DCP) and microcrystalline cellulose (MCC) was studied and compared with the tabletting behaviour of pellets made solely from microcrystalline cellulose (results from an earlier study by Johansson et al.). A series of pellets with porosities in the range 26-55% were prepared and tabletted at applied pressures of 25-200 MPa. Tablets were also formed from lubricated pellets. The degree of compression during compaction was calculated, and the porosity and tensile strength of the tablets and their permeability to air flow were determined. The porosity of the pellets was found to significantly affect the tabletting behaviour of the DCP/MCC pellets. However, the relationship between pellet porosity and tablet data for the DCP/MCC pellets was different from that for the MCC pellets. The DCP/MCC pellets were generally less prone to a reduction in volume during tabletting, and the pore structure of the DCP/MCC tablets was more closed. It was concluded that the DCP/MCC pellets were more rigid and underwent a different mode of deformation during tabletting than the MCC pellets. This mode of deformation was characterised by a more limited bulk deformation and a more extensive surface deformation at the pellet surfaces. The DCP/MCC pellets tended to give tablets of a lower mechanical strength. They were also less sensitive to lubrication in terms of their compactability, which may be explained either by less surface coverage by the lubricant before compression or rupture of the lubricant film during compression caused by the more extensive surface deformation of DCP/MCC pellets.

Calcium Phosphates↗

A designer's polymer as an oral drug carrier (tablet) with pseudo-zero-order release kinetics.

A new synthetic polymeric material has been investigated as an oral controlled-release system. The water soluble polymer consists of a non-cross-linked, ionic polymer possessing sulfonate functional groups: poly(sulfopropyl methacrylate potassium-co- methyl methacrylate) (PSPMK/MMA). Drug-resin complexes were obtained by preparing an aqueous solution of the polymer to which propranolol HCl as a model drug was added. Using either dextrose or microcrystalline cellulose as a tablet binder did not cause any problems in fabricating a compact drug-resinate tablet. The release of propranolol HCl from drug-resinate tablets (2.5 mm x 9.0 mm, 10% dextrose) was pseudo-zero-order kinetics from the beginning to the end for over 21 h. This was due to the greater contribution of drug release from the edge of the tablets. However, zero-order release tablets were obtained by increasing the radius to thickness ratio of the tablet to greater than 3.13. A mathematical model describing release kinetics from drug-resinate tablets predicted the effects of drug loading and the physical dimensions of the tablets by a heterogeneous dissociation/erosion-controlled mechanism. As the content of dextrose in the tablets increased, the dissociation/erosion rate constant (K0) increased due to the greater influx of water into the tablets along with counterions. As expected, the release rate was decreased as the stirring rate decreased from 100 to 50 rpm, resulting in the dissociation/erosion rate constant of 2.62-2.04 mg/cm2h, respectively. Therefore, this system has been proven to release drugs independent of the pH of simulated gastric/intestinal fluids (1.2 and 7.5) as well as the compression force of the tablet, which ranged from 1500 to 4400 lbs.

Cellulose↗

Pharmacokinetic and pharmacodynamic comparison of immediate-release and sustained-release adinazolam mesylate tablets after single- and multiple-dose administration.

The effect of adinazolam release rate on psychomotor performance and sedation was assessed by administering 40 mg adinazolam mesylate immediate-release (CT) tablets, 60 mg sustained-release (SR) tablets, and placebo in a double-blind crossover study in 15 healthy male subjects. A separate panel of 16 subjects received the above single doses and multiple-dose regimens of 40 mg CT tablets every 8 hr and 60 mg SR tablets every 12 hr according to a crossover design. Psychomotor performance was assessed by digit symbol substitution test, card sorting tasks, and sedation ratings. Following single-dose administration, dose-corrected adinazolam and N-desmethyladinazolam (NDMAD) AUC values were equivalent for SR and CT tablets. Peak adinazolam and NDMAD levels were lower and occurred later for the SR tablets. Decrements in card sorting were 50 and 3% at 1 hr and 17 and 20% at 6 hr for the CT and SR tablets, respectively. Maximal sedation scores were lower for the SR tablets compared to the CT. Dose-corrected AUC was comparable between single and multiple doses for both adinazolam and NDMAD; no differences were observed in 24-hr AUC at steady-state between CT and SR tablets. Fluctuation ratios were reduced for both adinazolam and NDMAD following SR tablets. Psychomotor and sedative effects were attenuated upon multiple dosing. Thus, the reduction in peak plasma NDMAD following SR tablet administration results in a lesser sedation and psychomotor impairment on acute administration, and tolerance to these effects occurs on multiple dosing.

Adult↗

Formulation and evaluation of novel tableted chitosan microparticles for the controlled release of clozapine.

Controlled release formulations of clozapine microparticulated tablets were prepared by using chitosan. Microparticles were characterized for particle size and size distribution. Microparticles were compressed into tablets using the directly compressible excipients. SEM photographs of the fractured part of the tablet revealed the presence of discrete particles in the tablets, suggesting that the system chosen is ideal for tableting. Drug release from the tableted microparticles exhibited an initial burst effect, but the release decreased with increasing extent of cross-linking. Tablets were coated with chitosan or cellulose acetate, which significantly lowered the initial burst effect when compared to uncoated tablets. Drug release from chitosan-coated tablets was slightly higher than the tablets coated with cellulose acetate. Tablets prepared were effective in delivering clozapine over a period of 12 h.

Cellulose↗

Effect of diluents on tablet integrity and controlled drug release.

The objective of this study was to evaluate the effect of diluents and wax level on tablet integrity during heat treatment and dissolution for sustained-release formulations and the resultant effect on drug release. Dibasic calcium phosphate dihydrate (DCPD), microcrystalline cellulose (MCC), and lactose were evaluated for their effect on tablet integrity during drug dissolution and heat treatment in wax matrix formulations. A newly developed direct compression diluent, dibasic calcium phosphate anhydrous (DCPA), was also evaluated. Compritol 888 ATO was used as the wax matrix material, with phenylpropanolamine hydrochloride (PPA) as a model drug. Tablets were made by direct compression and then subjected to heat treatment at 80 degrees C for 30 min. The results showed that MCC, lactose, and DCPA could maintain tablets intact during heat treatment above the melting point of wax (70 degrees C-75 degrees C). However, DCPD tablets showed wax egress during the treatment. MCC tablets swelled and cracked during drug dissolution and resulted in quick release. DCPD and lactose tablets remained intact during dissolution and gave slower release than MCC tablets. DCPA tablets without heat treatment disintegrated very quickly and showed immediate release. In contrast, heat-treated DCPA tablets remained intact through the 24-hr dissolution test and only released about 80% PPA at 6 hr. In the investigation of wax level, DCPD was used as the diluent. The drug release rate decreased as the wax content increased from 15% to 81.25%. The dissolution data were best described by the Higuchi square-root-of-time model. Diluents showed various effects during heat treatment and drug dissolution. The integrity of the tablets was related to the drug release rate. Heat treatment retarded drug release if there was no wax egress.

Calcium Phosphates↗

Matrix tablets of carrageenans. I. A compaction study.

Carrageenans can be used as excipients for controlled-release tablets. The aim of this study was to determine their compaction and consolidation behavior to prove their usefulness for tableting. The Carr indices of the three carrangeenans, two kappa-carrageenans(Gelcarin GP-812 NF and GP-911 NF) and one tau-carrageenan (Gelcarin GP-379 NF), indicate that the materials are free flowing. They are polymers in the rubbery state. Their glass transition-temperature is about 0 degree C analyzed by differential scanning calorimetry (DSC). The powders were analyzed regarding their compression behavior using an eccentric tableting machine. From data obtained during one compaction cycle, porosity-pressure and pressure-time plots were made. Compaction behavior is evaluated by fitting the pressure-time function to the pressure-time plot and by fitting the Heckel function to the porosity-pressure plot. The polymers show "viscoelastic" tableting behavior. Several additional tableting parameters were analyzed for strengthening the results obtained, namely, maximum work, maximum power, and the time between maximum upper punch force and maximum displacement of the upper punch. The crushing strength of the tablets is high; therefore, the carrageenans are able to form strong compacts. However, they remain in the rubbery state, as shown by thermomechanical analysis. In addition, elastic recovery is regarded at several times after ejection. Finally, after 10 days, it is about 30% as determined from the minimum of tablet height during the compression cycle. These results indicate that the carrageenans are suitable tableting excipients for controlled-release tablets. They show good compactibility and good consolidation behavior. Strong compacts with a high elastic recovery are formed; this means that the materials are able to embed drugs softly. Only a little stress and strain remains in the tablet. All three carrageenans show similar tableting behavior, and a flexible dosage form design is possible.

Calorimetry, Differential Scanning↗

Physicochemical characterization and evaluation of buccal adhesive tablets containing omeprazole.

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizerfor omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146-366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% +/- 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.

Adhesives↗

Novel chewable sustained-release tablet containing verapamil hydrochloride.

The aim of this research is to produce a compactable self-sealing chewable tablet of verapamil hydrochloride. Tablets were prepared by compressing beads coated with multiple layers including drug, hydroxypropyl methylcellulose, polyethylene oxide, ethylcellulose, lactose, and sodium starch glycolate. Dissolution studies were carried out according to the USP XXII paddle method for 14 h. A new tablet formulation was evaluated in three different forms: 1) whole tablet, 2) crushed tablet using a commercial tablet crusher, and 3) tablet chewed in the mouth and then expelled into dissolution fluid. Sustained release from the new formulation was maintained and was similar in all three different treatments, and similar to drug release from intact commercially available Isoptin SR, but crushing or chewing destroyed the sustained release property of Isoptin SR (as expected). This new formulation can be administered either by swallowing the whole tablet or by first crushing or chewing the tablet. Controlled release properties of this new formulation do not change by chewing or crushing the tablet first. Such a tablet could be valuable for all patients including those who have difficulty swallowing, such as pediatrics and geriatrics.

Administration, Oral↗

Ergometrine and methylergometrine tablets are not stable under simulated tropical conditions.

OBJECTIVES: This study is part of a programme on reduction of postpartum haemorrhage (PPH). Ergometrine and methylergometrine have a favourable effect on both blood loss and maternal morbidity and mortality and oral preparations were regarded as a possible treatment for use in tropical countries. The stability of oral preparations of the two ergometrine compounds under tropical conditions was unknown and was therefore examined in this study. STUDY METHODS: The 'experimental shelf lives' of ergometrine and methylergometrine tablets were examined by exposing the tablets to seven artificially controlled conditions. Samples were analysed by high performance liquid chromatography at nine different sampling times over a period of 1 year to determine the content of ergometrine and methylergometrine. RESULTS: Under refrigeration (test I), less than 90% of the stated amount of active ingredient was found in the tablets after 14 weeks in the case of ergometrine and 21 weeks in the case of methylergometrine. When stored in the dark at 40 degrees C and 75% relative humidity (test VI), the tablets fall outside accepted specification (= 90-110% of state amount of active ingredient) within 3 weeks in the case of ergometrine and 21 weeks in the case of coated methylergometrine tablets. The stability of uncoated ergometrine tablets was far less than that of coated methylergometrine tablets. Instability worsened under extreme humid conditions (test IV and VI), and hot conditions (test V), for both ergometrine and methylergometrine. From week 31 onwards the coating did not seem to protect the compound anymore, irrespective of the condition of exposure. CONCLUSIONS: Tropical conditions make the tablets unstable with humidity as the main adverse factor. The sugar-coated methylergometrine tablets are more stable under humid/hot conditions than the non-coated ergometrine tablets. Under all simulated conditions both oral ergometrine and methylergometrine tablets are unstable.

Chromatography, High Pressure Liquid↗

Effect of tablet integrity on the dissolution rate of sustained-release preparations.

The objective of this study was to evaluate the effect of tablet integrity on the dissolution rate. The model drug used for this study was aspirin. A dissolution study was performed with three commercially-available aspirin tablets (ZORprin, Bayer 8-h aspirin and Bayer aspirin), two of which were sustained-release tablets. For ZORprin, the average dissolution data indicated that the in vitro release rate of aspirin was consistent with the intended design of the sustained-release wax matrix tablets only when the tablets were intact. The split tablets showed a consistently higher release profile over time, with a 50% higher release at 6 h. However, the Bayer 8-h aspirin and plain aspirin tablet data showed that tablet integrity had no significant impact on the dissolution rate, because the intact and split tablets showed similar drug release profiles over time. In conclusion, care should be taken to administer sustained-release tablets, avoiding any breaking or crushing of the tablets unless this is directed by the manufacturer.

Anti-Inflammatory Agents, Non-Steroidal↗

Assessing the bioequivalence of 4- and 8-mg benidipine tablets in healthy volunteers after a single oral dose.

OBJECTIVE: To assess the bioequivalence of a new tablet formulation of benidipine hydrochloride with reference to a marketed product. METHODS: Two groups, consisting of 24 healthy volunteers each, received a 4- or 8-mg (one or two tablets) reference benidipine hydrochloride tablet and one or two test tablets in a 2 x 2 cross-over study. There was a 6-day washout period between doses. The plasma benidipine concentration was monitored using LC/MS/MS for 8 h after the dose. The area under the plasma concentration-time curve from time 0 to the last sampling time (AUCt) was calculated using the linear-log trapezoidal rule. The maximum plasma drug concentration (Cmax) and the time to reach Cmax (Tmax) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUCt and Cmax, and untransformed Tmax. RESULTS: The geometric mean AUCt was 2.23 ng/mL/h (test medication) and 2.47 ng/mL/h (reference medication) for the 4-mg tablet, and 9.57 and 9.97 ng/mL/h for the 8-mg tablet, respectively. A Cmax of 1.94 and 2.01 ng/mL was achieved for the test and reference medication for the 4-mg tablet, and 5.94 and 6.53 ng/mL for the 8-mg tablet, respectively. The 90% confidence intervals for AUCt and Cmax were 0.8441-1.0481 and 0.8739-1.2037 for the 4-mg tablet, and 0.8559-1.1273 and 0.9926-1.2176 for the 8-mg tablet, respectively, satisfying the bioequivalence criteria of the US Food and Drug Administration Guidelines, and the Korea Food and Drug Administration Guidelines. These results indicate that the 4- and 8-mg tablets of benidipine are bioequivalent to the reference formulations.

Administration, Oral↗

Comparative pharmacokinetics of voriconazole administered orally as either crushed or whole tablets.

Voriconazole is a triazole antifungal agent used to treat serious, invasive fungal infections including aspergillosis and candidemia. Limitations with existing formulations of voriconazole including restricted utility in patients with renal dysfunction (intravenous preparation) and the unavailability of an oral suspension in some countries make the administration of crushed tablets desirable in many clinical scenarios. However, concerns that this approach may alter the systemic absorption of voriconazole exist. Therefore, an open-label, randomized, two-way crossover comparative pharmacokinetic (PK) study using healthy volunteers was performed to compare these methods of tablet administration. In a random sequence, subjects received voriconazole tablets either crushed or whole. The voriconazole dose was 400 mg every 12 h for 1 day orally followed by 200 mg every 12 h orally for 5.5 days. Study periods were separated by 7 days. PK parameters were determined by the noncompartmental method. An equivalence approach with no-effect boundaries of 80 to 125% was used to assess bioequivalence. Twenty healthy subjects (10 males; aged 20 to 43 years) were enrolled in and completed the study. The adjusted mean areas under the plasma concentration-time curve from 0 to tau, where tau equals 12 h, for the crushed and whole tablet groups were 9,793 and 11,164 ng . h/ml, respectively (ratio, 87.72; 90% confidence interval [CI], 80.97, 95.04). The ratio of the maximum concentration of drug in serum for the crushed tablet versus whole tablet arms was 94.94 (90% CI, 86.51, 104.22). The only difference noted between groups was a slightly faster time to maximum concentration of drug in serum when subjects received crushed tablets, 0.5 h versus 1.5 h (90% CI, -0.75, -0.25). Treatment-related adverse events occurred in 12 subjects receiving whole tablets and 9 subjects receiving crushed tablets; all were mild. The administration of crushed voriconazole tablets is bioequivalent to whole-tablet administration.

Adolescent↗

Comparison of tablets and paper discs for antibiotic sensitivity testing.

The value of tablets and paper discs as reservoirs of antimicrobial agents for use in sensitivity testing was compared. Antibiotics that were unstable in paper discs showed no demonstrable loss of activity in tablets over a period of 50 days under adverse storage conditions. The antibiotic content of commercially prepared tablets is very high in comparison with the accepted content of paper discs used in Britain, but not all of the agent is released from tablets during tests. Comparison of the size of zones of inhibition around tablets and standard paper discs indicated that the amount of the various agents released from the tablets varied between 2-6% and 69% of the stated content. In tests of the sensitivity of a range of common pathogenic organisms, the results obtained with the tablet method--when interpreted as recommended by the manufacturer--were generally similar to those obtained with a paper disc method commonly used in British laboratories. In 47% of tests with aminoglycoside antibiotics, however, strains sensitive by the disc method were 'intermediate' or resistant by the tablet method. As with paper discs, it was necessary to press the tablets on to the medium. With adjustment of the 'effective antibiotic content of tablets to bring it into line with the accepted content in paper discs, the stability of antibiotics in the tablets might make them an acceptable alternative to paper discs.

Anti-Bacterial Agents↗

Bioavailability of d-pseudoephedrine and azatadine from a repeat action tablet formulation.

The objective of this study was to compare in man the bioavailability of d-pseudoephedrine and azatadine from a repeat action tablet formulation and from conventional tablets. The repeat action tablet, containing 1 mg of azatadine maleate in the coat, and 60 mg of d-pseudoephedrine sulfate in both the coat and the core, was given at 0 hour. A conventional tablet of 60 mg of d-pseudoephedrine sulfate was given at 0 and 4 hours and a conventional tablet of 1 mg of azatadine maleate was given at 0 hour. The plasma levels of d-pseudoephedrine were measured by gas-liquid chromatography and the amount of azatadine in the urine was determined by a mass fragmentographic procedure. The results showed that there were no statistically significant differences in the measured bioavailability parameters (area under plasma concentrations-time curve, maximum plasma concentration and time to reach maximum plasma concentration) for pseudoephedrine from repeat action tablets and conventional d-pseudoephedrine sulfate tablets; neither was there any statistically significant difference in the cumulative urinary excretion of azatadine from the repeat action tablets and conventional azatadine maleate tablets (p less than 0.10). These data clearly demonstrate the bioequivalence of the repeat action tablets and the conventional tablets of d-pseudoephedrine and azatadine.

Adolescent↗