Apparatus 4 Flow Through Cell: Some Thoughts on Operational Characteristics

Brown, Will

doi:10.14227/dt120205p28

Cited by 12 publications

(10 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The release profile of SI was evaluated in a flow-through cell configured in an open mode, where the medium is delivered fresh and the eluate removed. This apparatus was developed to resolve some deficiencies perceived in other compendial techniques [ 43 ]. The main advantages over other in vitro setups is that the medium can be easily changed, facilitating testing of formulation robustness with respect to variations in the intralumenal environment, and the hydrodynamics are more efficiently simulated [ 44 ].…”

Section: Resultsmentioning

confidence: 99%

Preparation of Spray-Dried Soy Isoflavone-Loaded Gelatin Microspheres for Enhancement of Dissolution: Formulation, Characterization and in Vitro Evaluation

et al. 2014

View full text Add to dashboard Cite

The most bioactive soy isoflavones (SI), daidzein (DAI) and genistein (GEN) have poor water solubility, which reduces their bioavailability and health benefits and limits their use in industry. The goal of this study was to develop and characterize a new gelatin matrix to microencapsulate DAI and GEN from soy extract (SE) by spray drying, in order to obtain solid dispersions to overcome solubility problems and to allow controlled release. The influences of 1:2 (MP2) and 1:3 (MP3) SE/polymer ratios on the solid state, yield, morphology, encapsulation efficiency, particle size distribution, release kinetics and cumulative release were evaluated. Analyses showed integral microparticles and high drug content. MP3 and MP2 yield were 43.6% and 55.9%, respectively, with similar mean size (p > 0.05), respectively. X-ray diffraction revealed the amorphous solid state of SE. In vitro release tests showed that dissolution was drastically increased. The results indicated that SE microencapsulation might offer a good system to control SI release, as an alternative to improve bioavailability and industrial applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Preparation of Spray-Dried Soy Isoflavone-Loaded Gelatin Microspheres for Enhancement of Dissolution: Formulation, Characterization and in Vitro Evaluation

et al. 2014

View full text Add to dashboard Cite

show abstract

“…A useful feature of the USP IV is it can be used in two configurations: (i) closed‐loop, where a specified medium volume is recycled throughout the analysis and (ii) open‐loop, where fresh solvent is continually passed through the cell. The latter method is therefore particularly applicable for the testing of low solubility compounds, where large media volumes are required [48] . Importantly, when in the open‐loop configuration, analyte solubility can be increased without the addition of surfactants or other solvents to the dissolution medium [45,49] .…”

Section: Methods For Maintaining Dissolution Sink Conditionsmentioning

confidence: 99%

“…The latter method is therefore particularly applicable for the testing of low solubility compounds, where large media volumes are required. [48] Importantly, when in the open-loop configuration, analyte solubility can be increased without the addition of surfactants or other solvents to the dissolution medium. [45,49] The system also bears some resemblance to the physiological environment of the gastrointestinal tract by continuously extracting drug from the dissolution vessel, thus mimicking absorption into the systemic circulation.…”

Section: Co-solventsmentioning

confidence: 99%

Overcoming sink limitations in dissolution testing: a review of traditional methods and the potential utility of biphasic systems

Phillips

Pygall²,

Cooper³

et al. 2012

Journal of Pharmacy and Pharmacology

168

109

View full text Add to dashboard Cite

Objectives The conventional dissolution test, particularly the USP apparatus I and II, remains an important tool in the armory of the pharmaceutical development scientist. For realistic dissolution characterization, sink conditions, where saturation solubility of a drug in the dissolution medium is at least three times more than the drug concentration, are critical. These conditions can be problematic to maintain with formulations containing poorly-soluble actives. This review summarizes the role of the dissolution test in the pharmaceutical industry, together with some traditional techniques/additives used to enhance solubility and facilitate the achievement of sink conditions. The biphasic dissolution system, an innovative model for the treatment of poorly-soluble species, will also be discussed. Key findings The biphasic dissolution model utilizes media comprising immiscible aqueous and organic layers whereby the drug, following initial aqueous dissolution, partitions into the organic layer. This step, which acts to remove all dissolved species from the aqueous layer, enables further aqueous dissolution to occur and hence the dissolution-partition cycle continues. Crucially, the aqueous layer does not saturate allowing sink conditions to be maintained and hence the experiment will, in theory, yield complete dissolution. Summary This review highlights important concepts regarding solubility/sink limitation and intends to provoke debate among analytical and formulation scientists as to the potential advantages, long-term development and widespread implementation of a biphasic dissolution system in drug development.

show abstract

“…When the system operates in the open mode, the data collected represents the amount dissolved/released at specific time intervals (estimate of release rate) and is in noncumulative form (8). Data can be transformed to the cumulative form; in this case, any mistakes associated with the estimation of the total drug released during a specific time interval will be transferred to the next time interval.…”

Section: Data Collectionmentioning

confidence: 99%

Flow-Through Cell Apparatus (USP Apparatus 4): Operation and Features

Fotaki¹

2011

Dissolution Technol.

View full text Add to dashboard Cite

Apparatus 4 Flow Through Cell: Some Thoughts on Operational Characteristics

Cited by 12 publications

References 10 publications

Preparation of Spray-Dried Soy Isoflavone-Loaded Gelatin Microspheres for Enhancement of Dissolution: Formulation, Characterization and in Vitro Evaluation

Preparation of Spray-Dried Soy Isoflavone-Loaded Gelatin Microspheres for Enhancement of Dissolution: Formulation, Characterization and in Vitro Evaluation

Overcoming sink limitations in dissolution testing: a review of traditional methods and the potential utility of biphasic systems

Flow-Through Cell Apparatus (USP Apparatus 4): Operation and Features

Contact Info

Product

Resources

About