The formulation of powder inhalation systems containing a high mass of nedocromil sodium trihydrate

Clarke, Martyn J.; Tobyn, Mike; Staniforth, John N.

doi:10.1002/1520-6017(200102)90:2<213::aid-jps12>3.0.co;2-7

Cited by 21 publications

(13 citation statements)

References 24 publications

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“…Thus it appears that the aerosol performance is associated with the presence of fine adhered particles among the carriers, but not the inherent particle size of carriers (29). The presence of fine lactose particles (VMD = 5.8 mm) can also facilitate physical disruption of the strong cohesive interaction between drug particles, such as nedocromil sodium trihydrate, by decreasing the number of drugYdrug contacts and increasing the separation distance between the neighboring drug particles (30). Given the strong influence of lactose fines on the overall performance of dry powder inhalation formulations, it is suggested that during particle size analysis of carrier, the weight percentage of lactose fine (<10 mm) as well as common statistic parameters (e.g., d 10 , d 50 , d 90 , and etc.)…”

Section: Respiratory Drug Deliverymentioning

confidence: 99%

Particle Size Analysis in Pharmaceutics: Principles, Methods and Applications

et al. 2006

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Physicochemical and biopharmaceutical properties of drug substances and dosage forms can be highly affected by the particle size, a critical process parameter in pharmaceutical production. The fundamental issue with particle size analysis is the variety of equivalent particle diameters generated by different methods, which is largely ascribable to the particle shape and particle dispersion mechanism involved. Thus, to enable selection of the most appropriate or optimal sizing technique, cross-correlation between different techniques may be required. This review offers an in-depth discussion on particle size analysis pertaining to specific pharmaceutical applications and regulatory aspects, fundamental principles and terminology, instrumentation types, data presentation and interpretation, in-line and process analytical technology. For illustration purposes, special consideration is given to the analysis of aerosols using time-of-flight and cascade impactor measurements, which is supported by a computational analysis conducted for this review.

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Section: Respiratory Drug Deliverymentioning

confidence: 99%

Particle Size Analysis in Pharmaceutics: Principles, Methods and Applications

et al. 2006

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“…In general, the interactions between drug particulates, drug agglomerates, drug-carrier adhesive units with single-or multi-drug particulates could be largely impacted by the level of shear forces exerted on powders during blending [60,61], which is mainly determined by mixer type.…”

Section: Blending Equipmentmentioning

confidence: 99%

“…TTM) [65], a problem that may be overcome by the use of medium shear blending (e.g. hand blending) [60]. This is because fine drug particulates used in DPI systems are usually highly cohesive.…”

Section: Blending Equipmentmentioning

confidence: 99%

“…The energy required to distribute individual drug particulates from drug agglomerates to carrier surfaces was shown to be higher in the case of adhesive mixtures containing drug particulates with smaller size and higher hygroscopicity [68]. Other studies demonstrated that the use of a mixer producing high shear forces is favourable in the case of adhesive mixtures containing two fine components in order to disperse the agglomerates of each fine material and thereby allow homogeneous distribution of one material in the other [60,63]. Sebti et al [22] carried out a study to find the optimal formulation/ blending conditions for blending ternary mixtures (Section 3.2.1.2) at a low drug (fluticasone propionate) concentration (1:499, w:w) and varying fine-to-coarse ratios (from 100:0 to 0:100, w:w).…”

Section: Blending Equipmentmentioning

confidence: 99%

“…A high shear mixer was therefore needed to break down the (drug-drug, drug-fine lactose, and fine lactose-fine lactose) agglomerates so that the adhesive (drugcoarse lactose) forces exceed the cohesive (drug-drug and drugfine lactose) forces. The reviewed literature supports these findings, showing increasing the shear forces generated by blending to lead to considerably improved deagglomeration and distribution of fine drug throughout the carrier and thereby improving the homogeneity of DPI formulation blends [42,60,69]. Nevertheless, this leads to another paradox -that relates to the detachment of fine drug particulates from carrier surfaces for delivery to the lung.…”

Section: Blending Equipmentmentioning

confidence: 99%

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On the effects of blending, physicochemical properties, and their interactions on the performance of carrier-based dry powders for inhalation — A review

Kaialy

2016

Advances in Colloid and Interface Science

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Blending drug and carrier powders to produce homogeneous drug-carrier adhesive mixtures is a key step in the production of dry powder inhaler (DPI) formulations. Although the blending conditions can result in different conclusions or probably change the outcome of a study entirely if being selected differently, there is a scarcity of data on the influence of blending processes on the physicochemical properties of bulk powder formulations and the follow-on effects on DPI performance. This paper provides an overview of the interactions between variables related to blending conditions (e.g. blending equipment, time, speed and sequence as well as environmental humidity) and powder physicochemical properties (e.g. size distribution, shape distribution, density, anomeric composition, electrostatic charge, surface, and bulk properties), and their effects on the performance of adhesive mixtures for inhalation in terms of drug content homogeneity, drug-carrier adhesion, and drug aerosolisation behaviour. The relevance of carrier payload, batch size and segregation was also discussed. Challenges and future directions were identified. This review therefore contributes towards a better understanding of the blending process, powder physicochemical properties, and their interlinked effects on the fundamental understanding of adhesive mixtures for inhalation. The knowledge gained is essential to ensure optimum blending and thereby controlled functionality of DPIs.

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