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Biomedical subjects

M Vidgren

Publications and source records attributed to M Vidgren.

At least 19 recordsLinked to original sources
PubMed2000

Pulmonary deposition of lactose carriers used in inhalation powders.

Dry powder dosage forms are generally formulated by mixing the micronized drug particles with the larger carrier particles. Lactose is a commonly used carrier. Carriers enhance the flowability of powder mixtures and therefore enable low dosing of active substances. During inhalation, the drug particles are dispersed from the surface of carrier particles. The aim of this study was to compare how different qualities of 99mTc-labelled lactose carrier systems deposit in the lungs. The sizes of the labelled and unlabelled alpha-lactose monohydrate particles were compared by using a laser diffraction method. Distribution of radiolabel between different particle size fractions was determined using the Andersen cascade impactor. The in vivo depositions of lactose carrier systems were investigated in ten healthy men using the technique of gammascintigraphy. In addition, redispersion of budesonide from the carrier materials was evaluated by using the Andersen cascade impactor. According to the validation data the particle size of the lactose carriers remained unchanged during the labelling process. Low pulmonary deposition varying between 2.5 and 3.3% was detected. Only a small amount of lactose was deposited in the lungs, thus pulmonary deposition is not a limiting factor for lactose selection. According to in vitro redispersion data the fine particle fraction of the delivered dose in the impactor varied between 10.3 and 26.0%. Thus, the redispersion of the budesonide particles can be altered by the properties of the carrier system.

Administration, Inhalation↗
PubMed1998

A new beclomethasone dipropionate multidose powder inhaler in the treatment of bronchial asthma.

The clinical efficacy, tolerability and acceptability of a new multidose powder inhaler (MDPI) containing beclomethasone dipropionate (BDP) were compared with those of a BDP aerosol administered with a large volume spacer (MDI-spacer) among adult asthmatics currently receiving from 500 to 1,000 microgram/day of an inhaled corticosteroid. During the study, the dosage of BDP from both devices was 400 microgram twice daily. Ninety-one patients were randomized to the MDPI group and 42 to the MDI-spacer group. The trial was performed as an open, randomized, parallel group multicenter study. The duration of the treatment period was 12 weeks, and the study was preceded by a 2-week run-in period. During the run-in period, the mean morning peak expiratory flow (PEF) was 487 and 466 1/min in the MDPI and MDI-spacer groups, respectively. After the 12-week treatment, the morning PEF was 491 1/min in the MDPI group and 463 1/min in the MDI-spacer group. The evening values were 500 and 479 1/min during the run-in period and 496 and 476 1/min after the 12-week treatment, respectively. Asthma symptom scores and the use of rescue medication were low in both groups, indicating good efficacy of the preparations tested. The median dose of histamine required to decrease forced expiratory volume in 1 s by 15% increased during the study from 800 to 1,098 microgram in the MDPI group and from 795 to 960 microgram in the MDI-spacer group. The most frequent adverse events in both groups were hoarseness and sore throat. There were no statistically significant differences between the treatment groups in serum cortisol values or in the number of patients with thrush. Seventy-two percent of the patients regarded the MDPI easier to use while 95% considered it more portable. Over 80% of the patients felt that the MDPI was also easier to clean and as easy or easier to learn to use than the MDI-spacer. To conclude, the novel powder inhaler is well tolerated and at least equally effective as the conventional MDI-spacer combination in the treatment of asthma with BDP. However, in everyday use, patients clearly favored the powder inhaler.

Administration, Inhalation↗
PubMed1995

Clinical equivalence of a novel multiple dose powder inhaler versus a conventional metered dose inhaler on bronchodilating effects of salbutamol.

In this study the bronchodilating effect of salbutamol (CAS 18559-94-9) after administration a single-dose (100 micrograms) from a novel multiple dose powder inhaler (MDPI; Easyhaler) and from a conventional metered dose inhaler (MDI) was compared. Forty adult asthmatic patients participated in a double-blind, randomized, cross-over, multicenter study with double-dummy technique. The study comprised two study days with a 4-h follow-up period of spirometric indices and measurements of blood pressure and heart rate. Both the powder and aerosol treatments caused a clear increase in spirometric parameters. The mean (SD) maximum forced exspiratory volume in one second (FEV1) after powder delivery was 2.82 (1.13) l and after aerosol 2.77 (1.03) l. The mean percentual change from the baseline in FEV1 was equal after both preparations. The mean area under the curve (AUC) of the absolute FEV1 values was 616 (264) and 609 (240) l x min after the powder and aerosol delivery, respectively. The treatments had no clinically significant effects on blood pressure or heart rate and were equally well tolerated. Thus the clinical effects indicate therapeutical bioequivalence of the powder and aerosol treatments. Furthermore, most patients found the handling of the MDPI device easier than or equal to that of the conventional MDI, which in all probability increase the patient compliance, which is one of the corner stones in the inhalation therapy of bronchial asthma.

Adolescent↗
PubMed1994

Pulmonary deposition and clinical response of 99mTc-labelled salbutamol delivered from a novel multiple dose powder inhaler.

Pulmonary deposition of 99mTc-labelled sulbutamol was determined after delivery from a novel multiple dose powder inhaler (Easyhaler). The clinical efficacy of the inhalation powder, evaluated simultaneously with gamma camera detection, was compared with that obtained after drug delivery from a metered dose inhaler-spacer combination. The study was performed as an open, non-randomized cross-over trial. A single dose of radiolabelled inhalation powder was inhaled on the first and the inhalation aerosol, as control, on the second study day. Sulbutamol sulphate was labelled with 99mtechnetium, and the inhalation powder was formulated by mixing radioactive drug particles with carrier material. Aerodynamic properties of the radiolabelled inhalation powder were similar to those of the unlabelled salbutamol powder. Delivered dose from the breath-actuated powder inhaler was adjusted to be equal to two puffs from a conventional aerosol actuator with a short plastic mouthpiece. Twelve non-smoking asthmatic patients participated in the trial. The mean pulmonary deposition of 24% was obtained after drug delivery from Easyhaler powder inhaler. Clinical efficacy of the medications was similar in terms of area under the FEV1 curve, maximum FEV1 and the improvement ratio. Thus it can be suggested that powder delivery from Easyhaler powder inhaler and the aerosol delivery through the spacer are equally effective.

Adult↗
PubMed1994

Easyhaler, a novel multiple dose powder inhaler: clinically equivalent to salbutamol metered dose inhaler and easier to use.

Twenty-one adult asthmatic patients participated in a trial to compare the clinical equivalence of a single dose of salbutamol inhaled either from a novel multiple dose powder inhaler (MDPI), Easyhaler, or from a conventional metered dose inhaler (MDI). The trial was carried out as a randomized, double-blind, crossover study. The study involved 2 study days with a 6-hour follow-up period of spirometric indices. In addition, blood pressure and heart rate were measured immediately before each lung function test. Our data indicate that salbutamol treatment with the MDPI achieves values which are equivalent to those achieved with the conventional pressurized MDI as regards improving pulmonary function and tolerability. The mean maximum forced expiratory volume in 1 s (FEV1) after the powder dose was 2.44 +/- 0.96 liters and after the aerosol dose 2.45 +/- 0.93 liters. The mean area under the curve of absolute FEV1 values was 822 +/- 340 and 829 +/- 335, respectively. The mean percent change from the baseline in FEV1, forced vital capacity and peak expiratory flow following administration of the preparations was of equal magnitude in both cases. The treatments tested had no effect on blood pressure or heart rate and were well tolerated. A further important finding was that most patients found the MDPI easier or no more difficult to use than the conventional MDI and this probably facilitates the transition from pressurized MDIs to the novel MDPI.

Adult↗
PubMed1994

Comparison of two beclomethasone dipropionate inhalation aerosol spacer combinations in the treatment of asthma.

Fifty-five asthmatics, previously treated with inhaled steroids (mean age 48 years, range 16-68 years, mean duration of the disease 10 years, range 1-35 years) participated in this multicentric 2-phase trial. The patients were in good clinical condition (basal FEV1 3.02 litres (1.38-6.29), 90% (48-131%) of predicted values; mean (range)). In the first phase (randomized, double-blind crossover study) 2 beclomethasone dipropionate (BDP) inhalation aerosol preparations (MDI) were administered through collapsible spacer. In the second phase (open, randomized, parallel group comparison), 1 of the preparations was administered via collapsible and the other via traditional large volume spacer. The total daily dose of inhaled beclomethasone was 1,000 micrograms. The evaluation of efficacy was based on peak flow monitoring (PEFR) carried out at home twice daily and on FEV1 measured in spirometry at control visits after the run-in period and after each 4-weeks treatment period. Side-effects and asthma symptoms were recorded on patient diaries. The patients were asked to evaluate the treatment efficacy and the use and handling of the MDI-spacer combinations with Visual Analog Scale (VAS) at the end of each treatment period. No statistically significant differences were found in PEFR or FEV1 between the treatments during whole study. The asthma symptom scores were low as well as the use of concomitant inhaled sympathomimetics which indicates good and equal efficacy of the preparations. The MDI-spacer combinations were equally well tolerated. According to the VAS scores, the collapsible spacer was easier to use and statistically significantly easier to handle than traditional large volume spacer.

Adolescent↗
PubMed1994

A novel multiple dose powder inhaler. Salbutamol powder and aerosol give equal bronchodilatation with equal doses.

Twenty adult patients with stable asthma were treated with cumulatively increasing doses of salbutamol delivered from a metered dose inhaler (MDI) and from a novel multiple dose powder inhaler (MDPI), Easyhaler, in a randomized 3-period crossover study. Four doses of salbutamol (delivered doses to the patient: 90, 90, 180, 360 micrograms; cumulative dose of 720 micrograms) were administered during each of the three study days and were inhaled every 30 minutes. Drug doses were released from the powder inhaler either before or during inhalation. Spirometry was performed at the beginning of each study day and 20 minutes after each dose. The lung function parameters after cumulative dosing of salbutamol were equal during each study day. The maximal percentage changes in forced expiratory volumes in one second after 720 micrograms of salbutamol were 24% with the MDI and 23% and 24% with the Easyhaler inhaler, respectively. Ten patients reported mild side effects when using the MDI, three when the powder was released before inhalation and five when the MDPI was actuated during inhalation. No significant changes in heart rate or blood pressure were observed during the study. We conclude that the novel multiple dose powder inhaler is clinically equally effective and slightly better tolerated than conventional metered dose inhaler when equal doses of salbutamol are inhaled by asthmatic patients.

Adult↗
PubMed1992

Absorption of ascorbic acid from a film-coated tablet and from a new enteric-coated pellet preparation in subjects with inadequate plasma levels of ascorbic acid.

The effects of a film-coated tablet and a novel enteric-coated pellet preparation of ascorbic acid (CAS 50-81-7) on the plasma concentration and on the urinary excretion of ascorbic acid were investigated. The pharmacokinetic properties of these dosage forms were also compared both after a single dose and in steady state. The study was carried out as a randomized, single blind parallel group trial in 11 volunteers with inadequate plasma levels of ascorbic acid. The duration of the treatment period was 7 days. After the first dose, higher plasma ascorbic acid concentration as well as AUC and Cmax values were achieved with the film-coated preparation. After the multiple dosing in steady state, plasma ascorbic acid concentration as well as AUC and Cmax values were higher with the new pellet preparation. In addition, the plasma ascorbic acid concentration remained on higher level with pellet preparation on the 7th day. Tmax values for the pellet preparation were also slightly higher on both of the pharmacokinetic test days. The amount of ascorbic acid excreted in urine was higher with the film-coated tablet. According to the results of this study it can be supposed that during the long-term supplementation the more complete absorption can be achieved with the new enteric-coated pellet preparation.

Adult↗
PubMed1991

Relative pharmacokinetics of three oral 400 mg ibuprofen dosage forms in healthy volunteers.

The pharmacokinetic properties of two solid form, 400 mg ibuprofen (IP) preparations, a soft gelatin capsule and a film-coated tablet, were compared to those obtained after the administration of liquid prepared from effervescent IP tablets. IP was absorbed rapidly (tmax 0.6-1.9 h). The fastest absorption was observed after the ingestion of the soft gelatin capsule; liquid and film-coated tablet produced 12.2-7.8 times longer absorption half-lives, 50-39% lower peak concentrations of IP in serum and 3.5-3.2 times higher tmax values. Bioavailabilities were close to similar after all products. All products were tolerated without side effects in this single-dose, crossover study on 14 healthy volunteers. The results of this study support the earlier findings that after oral administration, IP is absorbed equally well from solid formulations as from liquid form. Liquid formulations of IP often deliver slower absorption than expected probably due to incomplete dissolution of the active principle. This may have therapeutic significance, and it should be taken into account when studies on the relative bioavailability of IP from pharmaceutical drug products are planned.

Absorption↗
PubMed1991

Removal of inhaled 99mTc-labelled particles of disodium cromoglycate from the lungs.

Disodium cromoglycate particles were labelled with 99mTc by spray-drying technique. The in vitro dissolution profile as well as the leakage of radioactivity from the drug particles were determined using a through-flow cell method. The radioactive drug particles were mixed with a lactose carrier and inhaled from a dry powder device by five healthy volunteers. The removal of the inhaled drug particles from the lungs was evaluated by a gamma camera. A close relationship between the dissolution of the drug as such and the leakage of radioactivity was noted. Gamma scintigraphy indicated a biphasic exponential removal of radioactivity from the lung region. The slow component with the halftime of about 55 min was mainly due to the dissolution of drug particles in the lungs. The halftime of the fast component describing mucociliary clearance was less than 10 min. This process was the dominating one for the removal of the drug from the lungs. The experiment thus showed that the main fraction of the inhaled dose was deposited in the tracheobronchial region. Accordingly, only a small portion of the dose initially deposited in the lung can be absorbed and induce a therapeutic effect.

Aerosols↗
PubMed1991

Effects of inspirease holding chamber on the deposition of metered dose inhalation aerosols.

A modified cascade impaction method as well as a radiotracer technique has been used to assess the effects of the 700 ml collapsible holding chamber (InspirEase) on the in vitro and in vivo deposition of inhaled metered dose aerosols. The in vitro deposition of beclomethasone dipropionate 250 micrograms/dose aerosol administered either through the conventional aerosol actuator with the short plastic mouthpiece or through the InspirEase-device was evaluated with the modified cascade impactor which method imitated the human respiratory tract. For the in vivo study the disodium cromoglycate particles were labelled with pure gamma-radiator 99mTc using a coprecipitation technique based on spray drying. The deposition of the inhaled disodium cromoglycate particles in the human respiratory tract after administration of the drug doses from the devices tested was determined by means of gamma camera. InspirEase increased both in the in vitro and in vivo tests the fraction of the drug dose deposited into the therapeutically significant regions of the respiratory tract. In addition, the therapeutically insignificant fraction deposited in the upper passages and mouth clearly decreased. Thus using the InspirEase holding chamber not only a better lung penetration of the inhaled drug particles can be achieved but also the local side effects would be decreased.

Administration, Inhalation↗
PubMed1991

Nasal distribution of radioactive drug administered using two dosage forms.

The deposition patterns of 99mtechnetium labelled disodium cromoglycate particles administered either from a metered dose aerosol with a conventional nasal adaptor or from a dry powder nasal inhaler were studied using gamma camera. Disodium cromoglycate particles were firstly labelled with 99mTc using the spray drying technique. Both the metered dose aerosol and the dry powder dosage form were formulated using these radioactive drug particles. Seven healthy volunteers inhaled either three aerosol doses or one dry powder dose unit into one nostril. The drug dose reaching nasal cavity after administration from these two dosage forms was about the same. The deposition patterns as well as the changes in distribution due to the mucociliary transport were monitored by a gamma camera equipped with a low energy all purpose collimator. Initially drug doses deposited in a wider area of the nasal cavity when disodium cromoglycate particles were administered as a dry powder dosage form. In addition, retention index (%) which illustrates the movements of drug particles by mucociliary transport from the initial area of application seemed to be slightly higher for a metered dose aerosol than for a dry powder dosage form. At the end of the 30 minutes measuring period the area of the mucosal layer covered by radioactive drug particles was clearly wider for the dry powder dosage form than for the metered dose aerosol. Thus it is well possible to administer drug particles effectively into the nasal cavity as a dry powder dosage form.

Administration, Inhalation↗
PubMed1991

In vitro inhalation behaviour and therapeutical response of salbutamol particles administered from two metered dose aerosols.

In this study the particle size, as well as the in vitro deposition and the immediate bronchodilating effect on asthmatic patients, of two salbutamol inhalation aerosol preparations (Ventoline, Glaxo, UK, and salbutamol inhalation aerosol, Orion Pharmaceutica, Finland) were compared. The in vitro deposition study was performed using the modified Sierra Andersen cascade impactor. The bronchodilating effect of inhaled aerosol doses were monitored by measuring peak expiratory flow (PEF) values. In the clinical study, the pulse and blood pressure of the patients, as well as the side effects, were also recorded. Due to the anatomy and physiology of human lungs, the accepted optimum size for inhaled drug particles is under 5 microns, and preferably under 2 microns. Over 95% of the drug particles in both aerosol preparations were under 5 microns. 30% of the salbutamol particles in the Ventoline inhalation aerosol were under 2 microns, whereas in Orion salbutamol aerosol 14% of the drug particles were under 2 microns. Respectively 23% of Ventoline and 19% of the Orion salbutamol preparation penetrated into the therapeutically most significant imitated alveolar stages of the modified cascade impactor. Both salbutamol aerosols showed a clear clinical efficacy in the bronchodilating test. In addition, no significant differences existed in the bronchodilating effect of these inhalation aerosols. In conclusion, although there seemed to be a slight difference in the particle size distribution and in the in vitro inhalation behaviour, this variation did not have any effect on the clinical response.

Adult↗
PubMed1991

In vitro deposition and clinical efficacy of two sodium cromoglycate inhalation powders.

In this study, the in vitro deposition as well as the clinical efficacy of two dry powder inhalation preparations containing 20 mg of disodium cromoglycate were evaluated. The preparations were Blacil and Lomudal administered either with I.S.F. or Spinmatic powder inhalers, respectively. The in vitro inhalation study was performed using the cascade impacted method. During the in vitro test, similar fractions of the drug doses were retained in both inhalation devices. A remarkably larger proportion of the pelletized drug powder from the Lomudal preparation was deposited in the imitated upper airway than from the Blacil preparation consisting of the mixture of micronized disodium cromoglycate particles and lactose as a carrier. On the other hand, a larger fraction of the drug dose was deposited in the imitated lung area after the administration of the Blacil preparation than from Lomudal. The clinical study was performed as an exercise test in sixteen asthmatic patients. The preparations tested were statistically equally effective. The decrease in all the values of the pulmonary function parameters (PEF, FEV1) was, however, smaller after the administration of disodium cromoglycate from Blacil than from Lomudal preparation. According to the results of this study, the cascade impaction test seems to be valuable for predicting the efficacy of inhalation powders.

Administration, Inhalation↗
PubMed1991

Physical properties and clinical efficacy of two sodium cromoglycate inhalation aerosol preparations.

In this study, the particle size distribution and the droplet characteristics of the delivered aerosol cloud were first determined for two disodium cromoglycate inhalation aerosol preparations obtained from different manufacturers. In addition, the in vitro deposition properties and the clinical efficacy of these preparations were compared. The evaluation of the in vitro deposition was performed using a cascade impactor. The clinical efficacy was monitored by measuring the peak expiratory flow (PEF) values after the exercise test in fifteen asthmatic patients. The particle size and the spray characteristics of these two inhalation aerosol preparations were similar; the results of the in vitro test confirmed their similar physical properties. Both disodium cromoglycate preparations clearly alleviated the bronchoconstriction after the exercise test. According to the results of the clinical trial, supported by the laboratory scale studies, both disodium cromoglycate aerosols are of equal value in asthma inhalation therapy.

Administration, Inhalation↗
PubMed1991

Deposition and gastrointestinal transit of conventional sucralfate tablets.

Sucralfate was labelled with 99mTc by the stannous reduction method. Tablets were compressed using 1 g of radioactive sucralfate and suitable additives. On the first test day, five fully informed healthy volunteers were given one radioactive tablet of sucralfate each, following 10 h fasting. On the second test day, the sucralfate tablet was given after a standard meal. The gastrointestinal transit of the 99mTc-labelled sucralfate was evaluated using gamma camera technique. The labelling of sucralfate with 99mTc by the stannous reduction method enables the deposition and the transition of sucralfate in the gastrointestinal tract to be monitored. The tablets disintegrated almost immediately after administration and the released sucralfate distributed homogenously over the entire stomach area, in both fasted and fed subjects. Transit from the stomach into the intestine was noted already 10 min after administration in fasted subjects, whereas the gastric emptying of sucralfate was markedly delayed in fed subjects. To achieve a wider and more homogenous distribution in the GI-tract, sucralfate tablets should be taken before eating.

Adult↗