Development of a Novel Precipitation Technique for the Production of Highly Respirable Powders: The Atomized Rapid Injection for Solvent Extraction Process

Foster, Neil R.; Sih, Roderick

doi:10.1021/bk-2009-1006.ch017

Cited by 4 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, to have better control on the precipitation kinetics and particle size distribution, more sophisticated techniques and apparatus are needed to achieve rapid micro-mixing [19], which is mixing on the molecular scale dominated by diffusion [24]. Such methods include high-gravity controlled precipitation (HGCP) [25][26][27], flash precipitation using confined liquid impinging jets (CLIJ) [20,28,29] or multi-inlet vortex mixers (MIVM) [22,[30][31][32][33], supercritical fluid technology [34][35][36], and sonoprecipitation [37]. Of these, HGCP can produce both amorphous [38,39] and crystalline [23,[39][40][41] nanoparticles and has been applied in industrial scale production.…”

Section: Precipitationmentioning

confidence: 99%

Nanotechnology Versus other Techniques in Improving Drug Dissolution

Kwok¹,

Chan

2014

CPD

View full text Add to dashboard Cite

Many newly discovered drug molecules have low aqueous solubility, which results in low bioavailability. One way to improve their dissolution is to formulate them as nanoparticles, which have high specific surface areas, consequently increasing the dissolution rate and solubility. Nanoparticles can be produced via top-down or bottom-up methods. Top-down techniques such as wet milling and high pressure homogenisation involve reducing large particles to nano-sizes. Some pharmaceutical products made by these processes have been marketed. Bottom-up methods such as precipitation and controlled droplet evaporation form nanoparticles from molecules in solution. To minimise aggregation upon drying and promote redispersion of the nanoparticles upon reconstitution or administration, hydrophilic matrix formers are added to the formulation. However, the nanoparticles will eventually agglomerate together after dispersing in the liquid and hinders dissolution. Currently there is no pharmacopoeial method specified for nanoparticles. Amongst the current dissolution apparatus available for powders, the flow-through cell has been shown to be the most suitable. Regulatory and pharmacopoeial standards should be established in the future to standardise the dissolution testing of nanoparticles. More nanoparticle formulations of new hydrophobic drugs are expected to be developed in the future with the advancement of nanotechnology. However, the agglomeration problem is inherent and difficult to overcome. Thus the benefit of dissolution enhancement often cannot be fully realised. On the other hand, chemical strategies such as modifying the parent drug molecule to form a more soluble salt form, prodrug, or cyclodextrin complexation are well established and have been shown to be effective in enhancing dissolution. Thus the value of nanoformulations needs to be interpreted in the light of their limitations. Chemical approaches should also be considered in new product development.

show abstract