Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “POWDERS”

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 55 records · Page 3Linked to original sources
PubMed2002

Dry powder inhalation of antibiotics in cystic fibrosis therapy, part 1: development of a powder formulation with colistin sulfate for a special test inhaler with an air classifier as de-agglomeration principle.

The aim of this study was to investigate the pulmonary administration of antibiotics as dry powder to patients with cystic fibrosis (CF), as an alternative for nebulization. This part of the study describes the development of a powder formulation with colistin sulfate as model substance. The aim of the new dosage form was to increase pulmonary deposition, therapeutic efficiency and, by that, compliance by the CF patients. A physical powder mixture of colistin and a size fraction of lactose (106-150 microm) was prepared and the mixture was optimized with respect to colistin content (83.3%) for use in a special test inhaler. A laser diffraction apparatus with special inhaler adapter was applied for analysis of the size distribution of the aerosol cloud from the inhaler. The size distributions of the aerosol clouds from the test inhaler at flow rates between 30 and 60 l/min for the optimized formulation showed nearly the same median diameter as that for the primary drug particles. But the X(100)-value was much lower, because of an effective large particle separation from the inspiratory air by an air classifier in the test inhaler. The results suggest that dry powder inhalation might be a suitable and highly efficient alternative for nebulization of antibiotic drugs in CF therapy.

Administration, Inhalation↗
PubMed1996

Comparative evaluation of mean particle size of bulk drug powder in pharmaceutical preparations by Fourier-transformed powder diffuse reflectance infrared spectroscopy and dissolution kinetics.

This paper reports a quantitative correlation between specific FT-IR absorption peak intensity of phenytoin (PTH) to its particle size in the bulk as well as in powder blends. Absorption peak intensity in FT-IR spectra of phenytoin (PHT) increased with decrease of mean particle size of the powders. The relationships between the FT-IR absorbance at 1724 cm-1 of PHT and the specific surface area (Sw) obtained by the BET N2 gas absorption method or the reciprocal of mean particle size (D50) obtained by particle counting of SEM photomicrographs of ground samples showed straight lines, indicating that the absorbance followed the equation log (lo/l) = K1/D50 = K2Sw, where lo and l are intensities of the incident and transmitted light, respectively, and K1 and K2 are constants. In binary mixture of powders containing 50% PHT and 50% lactose, the relationship between the absorbance at 1724 cm-1 of PHT powder and Sw of the reciprocal of D50 also gave a linear plot. The dissolution behaviors of the binary mixture samples were measured in pH 1.2 buffer containing 0.1% sodium lauryl sulfate at 37 degrees C. The data from initial rates of dissolution of the binary mixture was utilized to calculate the particle size (Dg) using the Hixon-Crowell equation, and these particle size values were consistent with those obtained from Sw data as well as the absorbance data by the IR spectral method.

Chemical Phenomena↗
PubMed1999

The effect of polymorphism on powder compaction and dissolution properties of chemically equivalent oxytetracycline hydrochloride powders.

In South Africa, oxytetracycline is identified as an essential drug; many generic products are on the market, and many more are being developed. In this study, six oxytetracycline hydrochloride powders were obtained randomly from manufacturers, and suppliers were compared. It was found that compliance to a pharmacopoeial monograph was insufficient to ensure the optimum dissolution performance of a simple tablet formulation. Comparative physicochemical raw material analysis showed no major differences with regard to differential scanning calorimetry (DSC), infrared (IR) spectroscopy, powder dissolution, and particle size. However, the samples could be divided into two distinct types with respect to X-ray powder diffraction (XRD) and thus polymorphism. The two polymorphic forms had different dissolution properties in water or 0.1 N hydrochloride acid. This difference became substantial when the dissolution from tablets was compared. The powders containing form A were less soluble than that containing form B.

Calorimetry, Differential Scanning↗
PubMed1998

Risky business: pre-powdered gloves or powder-free gloves in the operating suite?

Two of the emerging issues for the health-care sector in the 1990s are occupational health and safety, and iatrogenic issues. Both of these issues are implicated in the use of pre-powdered latex gloves. Hospital health-care workers are exposed to latex in many ways: gloves, intravenous sets, ventilator circuits, dental products, resuscitation equipment, anaesthetic equipment. Post-operative complications, delayed wound healing, scar formation, and the potential for misdiagnosis, in the presence of starch powder, have been well documented in the literature with the need for through glove rinsing prior to surgery. Another route for glove powder to enter wounds is through a barrier breach. For an institution to ensure it provides the most durable and effective barrier for healthcare worker protection and patient safety, knowledge is needed regarding the various factors which lead to glove barrier failure. The primary aim of the study was to evaluate the in-use durability of the surgical gloves in current use against powder-free gloves. Descriptive statistics were used to analyse the data, in addition a cost analysis was calculated. The results of this study demonstrated clinically important differences between existing glove products in terms of barrier quality.

Australia↗
PubMed2000

[Fractal dimensions of powders used as pharmaceutical dusting powders].

The paper examines the use of the fractal dimension for the expression of the shape of random aggregates of primary particles of four powders for pharmaceutical dusting powders. The values within a range from 1.14 to 1.24 are compared with the results of the equilibrium gravitational classification within a range from 15 to 45 microns. Vacillation of the fractal dimension is influenced by the values of the specific surface determined from the parameters of the RRS-distribution of elutriation. The fractal dimension extends the morphological characteristics of powders. For the needs of pharmaceutical technology it is, however, necessary to specify better the conditions of its determination, above all in the selection of a suitable range of the dimension of evaluation ("walk") with regard to the largest dimension of the aggregates of powders.

Particle Size↗
PubMed2001

Stability and performance characteristics of a budesonide powder for inhalation with a novel dry powder inhaler device.

The design and the functionality of an innovative, multidose dry powder inhaler for the topical administration of drugs to the lung are described. The integrated triple inhalation control system, combined with easy handling, should increase acceptance of the device by patients. In-vitro data on a 200-microgram dose of budesonide powder for inhalation have demonstrated the excellent performance and robustness of this pocket-sized, breath-actuated device. The inhaler was developed for a wide range of drugs, and its patented dispersion system can be used with pelletized pure drugs or powder blends. The multidose dry powder inhaler is already on the market for use with one of the key asthma drugs: budesonide (Budecort 200 Novolizer; Sofotec GmbH & Co. KG, Frankfurt, Germany).

Asthma↗
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↗
PubMed1998

Uncooked rice powder in oral rehydration solution: an alternative to glucose or cooked rice powder.

Glucose-based or rice-based ORS is the standard treatment in acute dehydrating diarrhoea. However, glucose may not be easily available in remote villages and the rice needs to be cooked for rice-based ORS. We embarked on a study to examine whether uncooked rice powder could be used as an alternative to glucose or cooked rice powder in ORS. Initially, 50 adult male patients (aged 18 to 55 yr) were randomized to receive glucose-ORS or uncooked rice ORS, in two equal groups. Subsequently, 20 male children (aged 3 to 12 yr) were also enrolled in the study and received either WHO-ORS or study ORS. All the adult patients and the children could be successfully rehydrated with ORS containing uncooked rice powder. As compared to WHO-ORS, the study ORS significantly reduced stool output (6.60 +/- 1.24 vs. 5.88 +/- 1.34 l), ORS intake (9.17 +/- 1.54 vs 8.24 +/- 1.69 l) and duration of diarrhoea (45.68 +/- 6.91 vs 41.32 +/- 6.03 h). In children also similar results were obtained. No clinical complication (e.g., vomiting, abdominal pain etc.) or abnormality in serum electrolyte concentrations was encountered either in the adults or in the children. Uncooked rice powder containing ORS can be considered as an alternative to glucose-based ORS or rice-based ORS.

Adolescent↗
PubMed2005

Surface and chemical properties of surface-modified UHMWPE powder and mechanical and thermal properties of it impregnated PMMA bone cement, III: effect of various ratios of initiator/inhibitor on the surface modification of UHMWPE powder.

From our previous study, 3 wt% of ultra-high-molecular-weight polyethylene (UHMWPE) powder surface-modified by various ratios of methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA) solution was impregnated to improve the poor mechanical and thermal properties of conventional PMMA bone cement. In this study, various amounts of benzoyl peroxide (BPO) and hydroquinone were used for the adhesion reinforcement of UHMWPE powder with PMMA polymerized from MMA monomer (polyMMA) by the mixture of BPO and hydroquinone and ultimately to strengthen the poor mechanical and thermal properties of conventional PMMA bone cement. The tensile strengths of 3 wt% of UHMWPE powders surface-precoated with polyMMA prepared by various amounts of BPO- and hydroquinone-impregnated composite PMMA bone cements were similar to that of conventional PMMA bone cement. In particular, 3 wt% of UHMWPE powder surface precoated with polyMMA prepared with 0.75 wt% of BPO and 300 ppm of hydroquinone impregnated composite PMMA bone cement revealed the maximum tensile strength. However, no obvious significant difference was revealed, although the curing temperatures of the composite PMMA bone cements decreased from 103 degrees C to 91-97 degrees C. From these results, it was determined that the mixture of BPO and hydroquinone plays an important role in improving the poor mechanical properties of conventional PMMA bone cement. However, the thermal properties of the composite PMMA bone cements were not remarkably improved. The mechanical, chemical and thermal properties were individually confirmed using a scanning electron microscope (SEM), universal transverse mercator (UTM), Fourier transform infrared-attenuated total reflectance (FT-IR-ATR) and digital thermometer, respectively.

Bone Cements↗
PubMed2005

Application of powder X-ray diffraction in studying the compaction behavior of bulk pharmaceutical powders.

This study investigates the effects of crystal lattice deformation on the powder X-ray diffraction (PXRD) patterns of compressed polycrystalline specimen (compacts/tablets) made from molecular, crystalline powders. The displacement of molecules and the corresponding adjustment of interplanar distances (d-spacings) between diffracting planes of PNU-288034 and PNU-177553, which have crystal habits with a high aspect ratio favoring preferred orientation during tableting, are demonstrated by shifts in the diffracted peak positions. The direction of shift in diffracted peak positions suggests a reduction of interplanar d-spacing in the crystals of PNU-288034 and PNU-177553 following compaction. There is also a general reduction of peak intensities following compression at the different compressive loads. The lattice strain representing the reduction in d-spacing is proportional to the original d-spacing of the uncompressed sample suggesting that, as with systems that obey a simple Hooke's law relationship, the further apart the planes of atoms/molecules within the lattice are, the easier it is for them to approach each other under compressive stresses. For a third model compound comprising more equant-shaped crystals of PNU-141659, the shift in diffracted peak positions are consistent with an expansion of lattice spacing after compression. This apparent anomaly is supported by the PXRD studies of the bulk powder consisting of fractured crystals where also, the shift in peak position suggests expansion of the lattice planes. Thus the crystals of PNU-141659 may be fracturing under the compressive loads used to produce the compacts. Additional studies are underway to relate the PXRD observations with the bulk tableting properties of these model compounds.

Compressive Strength↗
PubMed2001

Quantitative analysis of crystalline pharmaceuticals in powders and tablets by a pattern-fitting procedure using X-ray powder diffraction data.

A pattern-fitting procedure for quantitative analysis of crystalline pharmaceuticals in solid dosage forms using X-ray powder diffraction data is described. This method is based on a procedure for pattern-fitting in crystal structure refinement, and observed X-ray scattering intensities were fitted to analytical expressions including some fitting parameters, i.e. scale factor, peak positions, peak widths and degree of preferred orientation of the crystallites. All fitting parameters were optimized by the non-linear least-squares procedure. Then the weight fraction of each component was determined from the optimized scale factors. In the present study, well-crystallized binary systems, zinc oxide-zinc sulfide (ZnO-ZnS) and salicylic acid-benzoic acid (SA-BA), were used as the samples. In analysis of the ZnO-ZnS system, the weight fraction of ZnO or ZnS could be determined quantitatively in the range of 5-95% in the case of both powders and tablets. In analysis of the SA-BA systems, the weight fraction of SA or BA could be determined quantitatively in the range of 20-80% in the case of both powders and tablets. Quantitative analysis applying this pattern-fitting procedure showed better reproducibility than other X-ray methods based on the linear or integral intensities of particular diffraction peaks. Analysis using this pattern-fitting procedure also has the advantage that the preferred orientation of the crystallites in solid dosage forms can be also determined in the course of quantitative analysis.

Benzoic Acid↗
PubMed1998

Dry powder inhalers: the influence of device resistance and powder formulation on drug and lactose deposition in vitro.

It is a principal in the formulation of a dry powder aerosol that the device should enable a high fine particle fraction (FPF) of drug to be delivered to the lung whilst any carrier, such as lactose, should remain in the upper airways. Both the device and the dry powder formulation itself contribute to the resultant FPF and few studies have considered the deposition of lactose carrier. It was the purpose of this study to determine the effect of the resistance of the device and the influence of powder formulation on the deposition of drug and carrier. Measurement of the pressure drop across the devices investigated in this study showed that the two types of Inhalator Ingelheim had the highest resistance, whilst lower pressure drops were found across the Diskhaler, Cyclohaler and Accuhaler devices. The lowest pressure drops were measured across the Rotahaler and Spinhaler devices. Employing Rotacaps 400 capsules as the formulated salbutamol product, the FPF of drug was greater from the high resistance devices, being in the order Inhalators Ingelheim>Cyclohaler>Rotahaler=Spinhaler. However, the Diskhaler, employing its own developed formulation, produced the highest FPF, approximately twice that from the Accuhaler. There was no statistical difference between the FPF of salbutamol (approximately 20% nominal dose) from the Rotacaps formulation when aerosolised using high resistance devices (Inhalators Ingelheim) operated at 30 l min-1, a medium resistance device (Cyclohaler) operated at 60 l min-1 and low resistance devices (Spinhaler and Rotahaler) operated at a flow-rate of 90 l min-1. The Ventolin Diskhaler using its own formulation operated at 60 l min-1 gave a FPF of 40.33%, but the FPF obtained was sensitive to flow, being only 25.65% of the nominal dose at 30 l min-1. Whereas no lactose was found in the FPF from the Accuhaler operated at 60 l min-1, 100, 400 and 3500 microg were obtained from the Diskhaler, Rotacaps and micronised lactose formulation, respectively, when operated at the same flow-rate. An in-house formulation comprising salbutamol sulphate blended with micronised lactose in a weight ratio of 1:67.5 and aerosolised from a Cyclohaler produced a similar FPF to the Diskhaler at 60 l min-1. When air flow was reduced to 30 l min-1, the FPF from the in-house formulation was reduced considerably less than that from the Diskhaler formulation.

Adrenergic beta-Agonists↗
PubMed2001

[Use of powder metallurgy for development of implants of Co-Cr-Mo alloy powder].

This paper discusses the application of powder metallurgy for the development of porous implantation materials. Powders obtained from Co-Cr-Mo alloy with different carbon content by water spraying and grinding, have been investigated. Cold pressing and rotary re-pressing methods were used for compressing the powder. It was found that the sintered materials obtained from water spraying have the most advantageous properties.

Humans↗
PubMed2005

Highly reproducible powder aerosolisation for lung delivery using powder-specific electromechanical vibration.

Dry powder inhalers (DPIs) have been in use since the 1970s, but it is only within the past few years that their use has constituted > approximately 10% of the inhaler units sold worldwide. Similarly, active DPIs have been in development for more than a decade, but no active device has yet been approved. Oriel is developing an active DPI technology that uses a very simple physical design coupled with a complex knowledge of powder flow and dispersion characterisation. The DPI uses electromechanical vibration with frequencies determined through the analysis of powder flow properties. Results so far have shown highly reproducible, efficient performance. The technology lends itself to both unit-dose and multidose platforms in a targeted cost-effective DPI.

Aerosols↗
PubMed2004

Formoterol dry-powder inhalation--Novartis/SkyePharma: Foradil MDDPI, Foradil MDPI, Foradil SkyeHaler, formoterol fumarate dry-powder inhalation.

In November 1998, Novartis Pharma of Switzerland and SkyePharma PLC of the UK signed an agreement to jointly develop a new formulation of the beta(2)-adrenoceptor agonist formoterol (Foradil). The new product, Foradil Certihaler, utilises a multidose dry-powder inhaler (MDPI or MDDPI) device, SkyeHaler, developed by SkyePharma. It also utilises SkyePharma's SkyeProtect powder formulation technology, which protects the drug from moisture. The product is waiting for approval for the treatment of asthma. Foradil MDPI may also have potential for the treatment of chronic obstructive pulmonary disease (COPD). Novartis has stated that Foradil Certihaler offers certainty of dosing and dose confirmation, and will also contain a dose counter that indicates the number of doses left. SkyePharma is responsible for development of the product in its finished form; this includes the supply of both the powder and the inhalation device as a product to Novartis. The product is manufactured at SkyePharma's Lyon facility in France. SkyePharma is receiving fees, development costs and milestone payments from Novartis. SkyePharma will also receive royalty income on worldwide sales. SkyePharma has granted Novartis an exclusive worldwide licence to market Foradil MDPI.Foradil Certihaler was approved in Switzerland in March 2004. This is the first approval in Europe, and will trigger an undisclosed milestone payment by Novartis to SkyePharma. Submissions for regulatory approval in the asthma indication were filed in the EU (on a country-by-country basis) and the US in December 2002. On 22 October 2003, SkyePharma announced that the US FDA had issued an 'approvable' letter for Foradil Certihaler. Launch of the product is anticipated for 2004. Clinical trials of Foradil MDPI for the treatment of asthma began in October 1999. In December 2000, phase III trials commenced in Europe. SkyePharma stated in April 2001 that phase III trials had commenced recently in the US. SkyePharma estimated in April 2001 that the worldwide sales potential of Foradil MDPI could be as much as 600 million US dollars. SkyePharma anticipates receiving royalties and manufacturing revenues of more than 10%.

Administration, Inhalation↗
PubMed1997

Characterisation of small changes in the physical properties of powders of significance for dry powder inhaler formulations.

In this paper we address the following issue: Why is surface characterisation important? All pharmaceutical processes (with the exception of mixing two gasses) involve interfacial contact, and, consequently, it is not surprising that surface energetics play an important role in determining the outcome of all events. For a dry powder inhaler system interfacial considerations may relate to drug-drug interactions (cohesion), drug-carrier or drug-device interactions (adhesion) and deaggregation phenomena during use. As all adhesive and cohesive interactions are interfacial phenomena it is reasonable to accept that the basis of interactions within dry powder inhalers is through interfacial forces, which can be divided into apolar (Lifshitz-van der Waals) and polar (electron donor-electron acceptor) components. Further to this it can be accepted that changes in the nature of any surface within the product (the drug, the carrier or the container) can be expected to result in changes in the surface interactions involving that phase. Thus, in essence, the success or failure of a formulated inhalation device is dependent upon the nature of the surface of the materials used, and, as such, measurement of these surfaces becomes of paramount importance. In this review comparatively little effort will be taken to prove the dominant role of surface energetics in inhalation products; this is primarily because much of the proof which exists is held as confidential by manufacturers. Consequently, this review will concentrate on surface characterisation of powders with respect to determination of surface energies and changes in solid-state properties.

Journal Article↗
PubMed1989

[Study on air-powder abrasive system for prosthetic clinical application. 3. Bacterial adherence to the air-powder abraded metal surface].

The purpose of this study is to investigate the relation between the metal surface texture and bacterial adherence. The surface of Au-Ag-Pd alloy was treated with or without air-powder abrasion. Seven standard strains and two clinical isolates were used. The alloys were mixed with [6-3H]-thimidine labelled bacteria. The radioactivity was measured with a scintilation counter. Streptococcus sanguis and clinical isolated Bacteroides gingivalis were adhered in a larger amount to the air-powder abraded alloy surface than to nonabraded alloy surface. These results indicated that careful consideration is needed for application of air-powder abrasive system on metal crown with secondary caries and periodontal disease.

Bacterial Adhesion↗