Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DOSAGE FORMS”

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.

At least 1,657 records · Page 92Linked to original sources
PubMed2000

[Consideration of drug absorption in customizing drug therapy].

The rate and extent of drug absorption from the small intestine are related to the release of the active ingredient from a dosage form, its solubility in the liquid phase of gastrointestinal contents, and the transport of the dissolved compound or the intact dosage form from the stomach into the duodenum. With pharmaceutical preparations releasing the active compound within the stomach, and enteric-coated "micro"-formulations (micropellets), gastric emptying is possible during the interdigestive and the digestive period. Potential differences of drug absorption between fasting administration and intake during the digestive period are unpredictable, because they are related to the release characteristics of the dosage form. However, larger enteric-coated preparations like tablets can leave the stomach only with a phase 3 contraction of fasting motility; intake during the digestive period will result in gastric retention of this type of dosage form until all food has left the stomach and fasting motility is restored. Consequently the onset of drug absorption is delayed. This interaction between food and large enteric-coated dosage forms is predictable from pyloric function in relation to the gastric motility. As it occurs regularly, it can be taken into account when prescribing enteric-coated dosage forms. If concomitant intake of food and enteric-coated drugs is unavoidable, but a rapid onset of drug absorption is necessary, micropellets are the dosage form of choice. When the therapeutic effect is insufficient, drug dosage form and timing of drug administration should be checked before prescribing a different active compound.

Biological Availability↗
PubMed1987

[Biopharmaceutical aspects of the medicinal forms of cephalexin].

The rate of cephalexin release from various dosage forms such as tablets, capsules and suspensions manufactured by several firms was studied. In vivo studies showed that pharmacokinetic indices of the absorption depended on the rate of cephalexin release from the dosage forms. The proposed procedure for in vitro estimation of the cephalexin release rate reflects bioavailability of the antibiotic dosage forms and may be used in quality control of finished dosage forms.

Animals↗
PubMed2003

Polarographic determination of ciclopirox olamine in pure substance and in different pharmaceutical preparations.

Two simple and sensitive methods are described for the determination of ciclopirox olamine in its pure form and different dosage forms. The proposed method depends upon the polarographic activity of ciclopirox olamine at the dropping mercury electrode (DME) in Britton Robinson buffer, whereby, well-defined cathodic waves were produced over the pH range 7-9. The polarographic wave was characterized as being irreversible diffusion-controlled with limited adsorption properties. The current-concentration relationship was found to be rectilinear over the range 8-32 and 2-12 microg ml(-1) using direct current (dct) and differential pulse polarographic (DPP) modes respectively, with minimum detectability of 0.53 microg ml(-1) (2.65 x 10(-6) M) and 0.1 microg ml(-1) (5 x 10(-7) M) using the dct and DPP modes, respectively. The average percent recovery was favorably compared to spectrophotometric method. The proposed method was further applied to dosage forms including ciclopirox lotion and cream. The average percentage recoveries for lotion were 100.34+/-0.84 and 99.96+/-1.06 using dct and DPP modes, respectively, and for cream were 100.53+/-0.59 and 100.02+/-0.89 using dct and DPP modes, respectively.

Buffers↗
PubMed2001

A highly sensitive spectrophotometric method for the determination of some phenothiazine antipsychotics using chloramine-T and indigocarmine.

A new simple, accurate and precise spectrophotometric method for the determination of six phenothiazine drugs in pure form and in dosage forms is described. The method is based on the oxidation of the studied drugs by a known excess of Chloramine-T in hydrochloric acid medium and subsequent determination of the unreacted oxidant by reacting it with indigocarmine in the same acid medium. The reacted oxidant corresponds to the drug content. The colored species exhibits maximum absorption at 610 nm. The apparent molar absorptivity values and Sandell sensitivity values are in the range 1.53 x 10(4)-2.96 x 10(4) l mol-1 cm-1 and 13.75-37.15 ng cm-2, respectively. The method is highly sensitive and suitable for 1-15 micrograms ml-1 concentrations with the detection limits being in the range, 0.0651-0.1724 microgram ml-1. The method was successfully applied to the studied drugs in their dosage forms. The results are reproducible within +/- 1% and compare favorably with those obtained by the procedures of the British Pharmacopeia.

Antipsychotic Agents↗
PubMed2003

Three useful bromimetric methods for the determination of salbutamol sulfate.

Three different methods developed for the determination of salbutamol sulfate (SBS), in pure drug form and in dosage forms, are discussed. The methods are based on the oxidation-bromination reaction of the drug by bromine generated in-situ by the interaction of bromate with bromide in acid medium. In titrimetry the drug is titrated directly with bromate in the presence of a large excess of bromide and in sulfuric acid medium using methyl red as indicator. Spectrophotometry is based on addition of a measured excess of bromate-bromide mixture to the sample solution in sulfuric acid medium followed by the estimation of surplus bromine by reacting it with a definite amount of methyl orange dye and measuring the absorbance at 510 nm. The amount of bromate reacting corresponds to the sample content. The kinetic method depends on the linear relationship between the concentration of the drug and time for oxidation and bromination as indicated by the bleaching of the methyl orange acid colour by the bromine generated in situ. Titrimetry is applicable in the 2-20 mg range. In spectrophotometry, Beer's law is obeyed in the 0.5-5.0 microg mL(-1) range whereas concentrations in the 5.0-25.0 microg mL(-1) range can be determined by the kinetic method. The effect of common excipients and additives in tablets is discussed. The procedures have been successfully applied to dosage forms; the results agree well with those obtained by use of a reference method. The methods can be used to determine SBS at mg or nicrog levels.

Albuterol↗
PubMed1987

The hydrodynamically balanced system: a novel principle of controlled drug release.

Madopar HBS (125 mg) is a controlled-release dosage form with 100 mg L-dopa and 25 mg benserazide. The 'hydrodynamically balanced system' (HBS) used for this novel dosage form of Madopar is a dosage form which, when in contact with gastric fluid and after dissolution of the gelatine shell of the capsule, forms a mucous body and a bulk density of less than 1 and releases the drug(s) at a desired rate whereas the dosage form remains in the stomach for a prolonged period of time. Drugs--in the present case L-dopa and benserazide--are released through the hydrated layer by diffusion principle. This system is valuable for drugs which are soluble at lower pH. By varying the composition of the excipients, desired release rates can be achieved. The in vitro dissolution rate of Madopar HBS formulation is as follows: L-dopa t75% = about 6 h and benserazide t75% = about 4 h. The floating behavior was tested in an in vitro test. These in vitro floating properties could be confirmed in man and were investigated in 10 healthy volunteers by means of gamma camera measurements using a poly-marker technique carried out in connection with a Valium CR study. It is expected that this novel drug delivery system proffers a valuable dosage form which delivers the drug at a specific rate allowing a better control of fluctuations in parkinsonian patients.

Administration, Oral↗
PubMed2000

Development and evaluation of oral multiple-unit and single-unit hydrophilic controlled-release systems.

This study compared the release behavior of single-unit (tablets, capsules) and multiple-unit (minitablets in capsules) controlled-release systems of furosemide. The swelling and erosion behaviors of these systems, which contained the swellable hydrophilic polymers sodium alginate (high viscosity) and Carbopol 974P, were compared. Swelling and erosion experiments showed a high degree of swelling and limited erosion for the Carbopol preparations, whereas less swelling but greater erosion was observed for the sodium alginate preparations. The sodium alginate preparations were eroded in 6 hours, while Carbopol preparations exhibited limited erosion within this period of time. These results appear to be attributed to the physicochemical characteristics of the polymers used in this study. Polymer characteristics greatly influenced the release of furosemide (model drug) from the formulations prepared and tested. Sodium alginate had a less pronounced sustained release effect compared with Carbopol (ie, in 8 hours all 3 sodium alginate dosage forms displayed complete release of furosemide, while only 30% of the drug was released from Carbopol dosage forms). Finally, all 3 Carbopol dosage forms (single- and multiple-unit) displayed similar release behavior while sodium alginate dosage forms displayed a different and more distinctive behavior. Minitablets and tablets showed a greater sustained release effect compared with capsules. Evaluation of the release data indicates that the release mechanism for sodium alginate formulations may be attributed to erosion/dissolution, while for Carbopol it may be attributed mainly to polymer relaxation and diffusion of the drug from the polymer surface.

Acrylic Resins↗
PubMed1992

Stability of captopril in some aqueous systems.

A stability-indicating high performance liquid chromatographic method has been proposed to quantify captopril. The method has been used to determine the stability of captopril in oral liquid dosage forms prepared from either commercially available tablets or powder. The dosage forms in water were more stable than when the vehicle was a syrup. Furthermore, the dosage form prepared using powder in water was more stable than when tablets were used. While the decomposition of captopril followed first-order equation when the dosage forms were prepared in syrup (in two of the three solutions studied), this equation was not followed when water was the vehicle. This is probably due to an uncontrolled factor, oxygen, because captopril is very sensitive to oxidation. Captopril solution prepared in water using tablets was stable for about 20 days when stored at 5 degrees C, and that prepared using powder in water was stable for about 27 days. One commercial syrup hastened the process of decomposition with an additional unidentified product of decomposition.

Captopril↗
PubMed2004

N-trimethyl chitosan chloride as absorption enhancer in oral peptide drug delivery. Development and characterization of minitablet and granule formulations.

In this study, minitablet and granule formulations were developed as solid oral dosage forms for the delivery of peptide drugs with the absorption enhancer N-trimethyl chitosan chloride (TMC). Minitablets were deemed suitable as a dosage form due to their ability, as components of multiple unit dosage forms (MUDFs), to disperse from each other, before disintegration, effectively increasing the area in which the polymer can assert its absorption-enhancing effect. The polymer should be released from the dosage forms prior to the release of the peptide, which was, together with achieving maximum release of both ingredients, the main focus of this study. Desmopressin (1-(3-mercaptopropionic acid)-8-D-arginine vasopressin monoacetate (DDAVP) was used as model peptide drug. The optimized minitablet formulation consisted of two types of granules, namely DDAVP and TMC granules. DDAVP granules, containing tetraglycerol pentastearate (TGPS), were specifically aimed at delaying the release of the peptide from the dosage form. Burst release of TMC was attempted with TMC granules. Both these granule types were included in the granule formulation. Release profiles for both the optimized minitablet formulation as well as the granule formulation showed that the release of DDAVP was effectively delayed from the formulation compared to the formulation where no attempt at delaying the release was made. In comparison, more TMC was released, and at a faster rate, from the granule formulation than the optimized minitablet formulations. Both the optimized minitablet formulation and the granule formulation show suitable release profiles for the delivery of peptide drugs with TMC as absorption enhancer in solid oral dosage forms.

Adhesives↗
PubMed1992

[Experimental study of human recombinant insulin].

The experimental study of recombinant human insulin revealed its high specific activity. The kinetics of the hypoglycemic effect of various dosage forms of the insulin developed at the National Research Centre of Antibiotics and the dosage forms manufactured by Eli Lilly was similar. The pharmacological investigation of the dosage forms showed that they had no side effects on the vitally important organs and systems. It was concluded that the dosage forms of the gene engineered human insulin developed at the National Research Centre of Antibiotics did not differ by their characteristics from the analogous dosage forms manufactured in other countries.

Animals↗
PubMed2003

Benefits of different drug formulations in psychopharmacology.

Adequate dosage forms are essential for achieving successful pharmacotherapy. Innovative dosage forms or delivery systems may direct a drug to its specific site of action, optimize the timing of the drug release, or increase comfort or convenience for the patient. Thus, such innovations may improve efficacy and tolerability and lead to improvements in health-related quality of life. Specialized dosage forms (e.g., depot injections, extended-release formulations) of several psychiatric agents have been extensively used. The latest addition is an orally disintegrating formulation of the antidepressant mirtazapine. This dosage form dissolves rapidly in the mouth and is convenient for the large proportion of patients who have difficulty in swallowing tablets.

Anti-Bacterial Agents↗
PubMed1988

Impact of removing oral neuroleptic liquids from the formulary of a large psychiatric hospital.

Oral liquid formulations of neuroleptic medications have been claimed to offer advantages in treatment of psychotic patients, particularly as a means of ensuring compliance. After a review of the literature, this 900-bed psychiatric facility found no substantial support to indicate that liquids are superior to solid dosage forms. Because of their higher cost, liquid neuroleptics were removed from this formulary. Few changes in prescribing practices were measured after removal of liquids; dosages remained constant and injectable neuroleptic and sedative use actually decreased. Replacing liquid neuroleptic dosage forms with solid dosage forms resulted in an estimated annual savings of nearly $60,000 at this institution. The authors conclude that liquid neuroleptics appear to offer no benefits over solid dosage forms in adult psychiatric patients and can be removed from drug formularies without disruptive effects on psychotropic prescribing practices or clinical care. However, further research is needed to determine the benefits of liquid neuroleptics in special clinical or psychiatric settings.

Antipsychotic Agents↗
PubMed2001

Development and characterization of a novel peroral peptide drug delivery system.

Novel drug delivery systems were developed for peroral administration of peptide and protein drugs for site specific mechanical fixation at the gut wall and with specific release patterns. These so-called shuttle systems were designed by using superporous hydrogels (SPH) and SPH composite (SPHC) as the conveyor of a core which contained the model compound N-alpha-benzoyl-L-arginine ethylester (BAEE). Two different types of shuttle systems were evaluated: (a) core inside the shuttle system, and (b) core attached to the surface of shuttle system. Each of these systems was made of two parts: (1) the conveyor system made of SPHC which is used for keeping the dosage form at specific site(s) of the GI tract by mechanical interaction of the dosage form with the intestinal membranes, and (2) the core containing the active ingredient and incorporated in the conveyor system. The effect of formulation composition of the core on the release profile of BAEE was investigated by changing the type and amount of excipients in the formulations. In addition, the effect of various enteric-coat layers on the release profile and dissolving of the dosage form was investigated. The systems were also characterized for trypsin inactivation and Ca(2+) binding. The release profile of BAEE from the core formulation consisting of PEG 6000 microparticles or small tablets showed the desired burst release. When these core formulations were incorporated into the conveyor system made of SPH and SPHC, a suitable time-controlled release profile was obtained. Changing the type, concentration and thickness of the enteric-coat layer influenced the starting time of BAEE release from the dosage form, which indicates the necessary lag time for dissolving of the dosage form at any desired specific site of drug absorption in the intestine. Both SPH and SPHC were found to partly inhibit the activity of trypsin, due to two mechanisms: Ca(2+) binding and entrapment of the enzyme in these polymers. In conclusion, the presently developed delivery systems demonstrate suitable in vitro characteristics with an appropriate time-controlled release profile, making these systems very promising for effective peroral delivery of peptide and protein drugs.

Calcium↗
PubMed2005

Site-specific delivery of anti-inflammatory drugs in the gastrointestinal tract: an in-vitro release model.

Mesalazine and budesonide are anti-inflammatory drugs that are used to induce and maintain remission of inflammatory bowel diseases (IBD), such as Crohn's disease and ulcerative colitis. Both drug substances are intended to act locally at the inflamed sites of the gastrointestinal tract. The therapeutic objective for per oral treatment with these drugs is to achieve a high concentration of the active drug at the sites of inflammation while minimizing systemic absorption. The aim of this study was to develop a test system able to reflect the changing environment that a dosage form incorporating the anti-inflammatory agent is exposed to as it moves through the gastrointestinal tract. The USP dissolution apparatus 3 was used for all experiments. Compendial, as well as biorelevant, media were used to simulate passage through the gastrointestinal tract under various physiological conditions. Different dosage forms of mesalazine (5-aminosalicylic acid, 5-ASA) and budesonide available on the German market were tested. Although all dosage forms were indicated for the same therapeutic objectives, each of the dosage forms exhibited a characteristic release pattern under in-vitro conditions simulating a passage through the fasted-state gastrointestinal tract. Results from this test series indicate that, in the case of various dosage forms of mesalazine and budesonide used for the therapy of Crohn's disease and ulcerative colitis, release patterns as the dosage form moves through the gastrointestinal tract may vary widely. As the various phenotypes of IBD have different requirements in terms of pattern of distribution of the inflamed sites, and because other aspects of gastrointestinal physiology vary within the patient population, the test methods and approach described here should be very useful in designing therapy tailored to the needs of each individual patient.

Anti-Inflammatory Agents↗
PubMed2004

Determination of the binding parameter constants of Renagel capsules and tablets at pH 7 by high performance capillary electrophoresis.

Sevelamer hydrochloride is a cross-linked polymeric amine; it is the active ingredient in Renagel capsules and tablets. Sevelamer hydrochloride is indicated for the control of hyperphosphatemia in patients with end-stage renal disease (ESRD). The binding parameter constants of sevelamer hydrochloride were determined using high performance capillary electrophoresis (HPCE) and the Langmuir approximation for three different dosage forms at pH 7.0. The three dosage forms were Renagel 403 mg capsules, Renagel 400 mg tablets and Renagel 800 mg tablets. The results demonstrate the in vitro bioequivalence of all three dosage forms at pH 7.0. These results are in very good agreement with previously published results obtained by ion chromatography.

Binding Sites↗
PubMedDate not supplied

Rotary pursuit, a measure of human performance, and plasma concentrations of promethazine.

Promethazine in doses of 50 mg has demonstrated detrimental effects upon the performance of visual tasks. The purpose of the study was to examine the relationship between the blood concentration levels of promethazine and two human performance tasks. Fifteen paid healthy male volunteers completed a randomized five-way crossover design which included a 25 mg and 50 mg dose of the innovator dosage form, a 50 mg dose of a generic dosage form, a 50 mg solution dosage form, and a placebo. Serial blood samples were obtained in addition to performance measures of rotary pursuit and a simple force choice reaction time. Analysis of the forced choice reaction depicted a mild relationship with the blood concentration levels of promethazine. However, the measures of rotary pursuit, a more sensitive determinant of human motor performance, proved to be more related to both the promethazine blood concentration and the inherent learning which was confounded in the experiment. The degree of impaired pursuit performance and reaction time differences could be defined in terms of a linear relationship to the promethazine concentration.

Humans↗
PubMed2004

Evaluation of the vibratory feeder method for assessment of powder flow properties.

The flow properties of pharmaceutical powders and blends used in solid oral dosage forms are an important consideration during dosage form development. The vibratory feeder method, a flow measurement technique that quantifies avalanche flow, has been adapted for measurement of the flow properties of common pharmaceutical powders used in solid oral dosage forms. The flow properties of 17 different powders were measured with the instrument, and the results are reported as a powder flow index (PFI). The PFI trends of the powders correlate well with flow properties reported in the literature. The flow properties of the powders were also measured with a commercially available avalanche instrument, the Aero-Flow, and the results were reported as the mean time to avalanche (MTA). Since the two instruments analyze the avalanche by different algorithms, the results were compared with nonparametric statistical evaluation of ranked data, and they were found to be in excellent agreement. A recommended procedure for measurement of powder flow with the vibratory feeder is presented.

Powders↗
PubMed2002

[Comparative study on pharmacodynamic effects of yinqiao powder decoction and its granule].

OBJECTIVE: To compare the pharmacodynamic effects of Yinqiao Powder on dividual decoction, admixture decoction and granule. METHODS: The mouse and rat inflammatory models were established by dimethylbenzene and carrageenin respectively. The rabbit model was established by typhoid Vi polysaccharide bacterin through ear vein and serolysin was induced by chick red cell. The effects of different dosage forms on inflammation antipyresis and inhibiting serolysin were observed. RESULTS: All three dosage forms of Yinqiao Powder could inhibit mouse auricle swelling and rat toe swelling, possessed the antithemic action and could accelerate the formation of serolysin(p < 0.01). But there were no difference among these three dosage forms in pharmacodynamic effects. CONCLUSIONS: Three dosage forms of Yinqiao Powder had the similar effects in above-mentioned pharmacodynamic markers.

Analgesics, Non-Narcotic↗