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Nanosizing of drugs: Effect on dissolution rate.

Dizaj SM, Vazifehasl Zh, Salatin S, Adibkia Kh, Javadzadeh Y - Res Pharm Sci (2015 Mar-Apr)

Bottom Line: According to the reviewed literature, by reduction of drug particle size into nanometer size the total effective surface area is increased and thereby dissolution rate would be enhanced.Additionally, reduction of particle size leads to reduction of the diffusion layer thickness surrounding the drug particles resulting in the increment of the concentration gradient.Each of these process leads to improved bioavailability.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, I.R. Iran ; Student Research Committee, Tabriz University of Medical Science, Tabriz, I.R. Iran.

ABSTRACT
The solubility, bioavailability and dissolution rate of drugs are important parameters for achieving in vivo efficiency. The bioavailability of orally administered drugs depends on their ability to be absorbed via gastrointestinal tract. For drugs belonging to Class II of pharmaceutical classification, the absorption process is limited by drug dissolution rate in gastrointestinal media. Therefore, enhancement of the dissolution rate of these drugs will present improved bioavailability. So far several techniques such as physical and chemical modifications, changing in crystal habits, solid dispersion, complexation, solubilization and liquisolid method have been used to enhance the dissolution rate of poorly water soluble drugs. It seems that improvement of the solubility properties ofpoorly water soluble drugscan translate to an increase in their bioavailability. Nowadays nanotechnology offers various approaches in the area of dissolution enhancement of low aqueous soluble drugs. Nanosizing of drugs in the form of nanoparticles, nanocrystals or nanosuspensions not requiring expensive facilities and equipment or complicated processes may be applied as simple methods to increase the dissolution rate of poorly water soluble drugs. In this article, we attempted to review the effects of nanosizing on improving the dissolution rate of poorly aqueous soluble drugs. According to the reviewed literature, by reduction of drug particle size into nanometer size the total effective surface area is increased and thereby dissolution rate would be enhanced. Additionally, reduction of particle size leads to reduction of the diffusion layer thickness surrounding the drug particles resulting in the increment of the concentration gradient. Each of these process leads to improved bioavailability.

No MeSH data available.


Reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient and dissolution rate.
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Figure 1: Reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient and dissolution rate.

Mentions: Generally the particle size and shape are important in every stage of a solid dosage form fabrication. Particle size affects mixing, granulation, compression and coating of solid dosage forms (45464748). In the body, dissolution rate of a drug is a function of solubility and particle size. It seems that the simplest way to increase the dissolution rate is particle size modification. By particle size reduction (micronization and nanosizing) of both actives or excipients, dissolution rate can be enhanced (4649). According to Noyes-Whitney equation when particle size is reduced, the total effective surface area is increased and thereby dissolution rate is enhanced. Additionally, reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient (450). Additionally, reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient (450). This process illustrated in Fig. 1.


Nanosizing of drugs: Effect on dissolution rate.

Dizaj SM, Vazifehasl Zh, Salatin S, Adibkia Kh, Javadzadeh Y - Res Pharm Sci (2015 Mar-Apr)

Reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient and dissolution rate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4584458&req=5

Figure 1: Reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient and dissolution rate.
Mentions: Generally the particle size and shape are important in every stage of a solid dosage form fabrication. Particle size affects mixing, granulation, compression and coating of solid dosage forms (45464748). In the body, dissolution rate of a drug is a function of solubility and particle size. It seems that the simplest way to increase the dissolution rate is particle size modification. By particle size reduction (micronization and nanosizing) of both actives or excipients, dissolution rate can be enhanced (4649). According to Noyes-Whitney equation when particle size is reduced, the total effective surface area is increased and thereby dissolution rate is enhanced. Additionally, reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient (450). Additionally, reduction of particle size reduces the diffusion layer thickness surrounding the drug particles and thereby increases concentration gradient (450). This process illustrated in Fig. 1.

Bottom Line: According to the reviewed literature, by reduction of drug particle size into nanometer size the total effective surface area is increased and thereby dissolution rate would be enhanced.Additionally, reduction of particle size leads to reduction of the diffusion layer thickness surrounding the drug particles resulting in the increment of the concentration gradient.Each of these process leads to improved bioavailability.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tabriz University of Medical Science, Tabriz, I.R. Iran ; Student Research Committee, Tabriz University of Medical Science, Tabriz, I.R. Iran.

ABSTRACT
The solubility, bioavailability and dissolution rate of drugs are important parameters for achieving in vivo efficiency. The bioavailability of orally administered drugs depends on their ability to be absorbed via gastrointestinal tract. For drugs belonging to Class II of pharmaceutical classification, the absorption process is limited by drug dissolution rate in gastrointestinal media. Therefore, enhancement of the dissolution rate of these drugs will present improved bioavailability. So far several techniques such as physical and chemical modifications, changing in crystal habits, solid dispersion, complexation, solubilization and liquisolid method have been used to enhance the dissolution rate of poorly water soluble drugs. It seems that improvement of the solubility properties ofpoorly water soluble drugscan translate to an increase in their bioavailability. Nowadays nanotechnology offers various approaches in the area of dissolution enhancement of low aqueous soluble drugs. Nanosizing of drugs in the form of nanoparticles, nanocrystals or nanosuspensions not requiring expensive facilities and equipment or complicated processes may be applied as simple methods to increase the dissolution rate of poorly water soluble drugs. In this article, we attempted to review the effects of nanosizing on improving the dissolution rate of poorly aqueous soluble drugs. According to the reviewed literature, by reduction of drug particle size into nanometer size the total effective surface area is increased and thereby dissolution rate would be enhanced. Additionally, reduction of particle size leads to reduction of the diffusion layer thickness surrounding the drug particles resulting in the increment of the concentration gradient. Each of these process leads to improved bioavailability.

No MeSH data available.