Limits...
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.


The preparation steps for a drug nanosuspension.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4584458&req=5

Figure 4: The preparation steps for a drug nanosuspension.

Mentions: Nanosuspensions contain colloidal dispersion of drug nanocrystals in a liquid dispersion medium such as water, aqueous solutions, or nonaqueous media which stabilized by surfactants and/or polymeric stabilizers (33780). Nanosuspension method is one of the promising methods in improving the dissolution rate of poorly-water soluble drugs. A nanosuspension not only can overcome the poor solubility and bioavailability of low water soluble drugs, but also could modify the pharmacokinetic profiles of drugs and thus improve their safety and efficacy (8182). Nanosuspensions are prepared by precipitation, high pressure homogenization, emulsion and milling techniques (8384). The particles in nanosuspensions are stabilized with mixture of surfactants or polymers (3885). Also by addition of a suitable tonicity modifier agent, the formulation may be used for intravenous injection. The formulations could also be further processed into standard dosage forms such as capsules and tablets for oral administration (40). Fig. 4 shows the preparation steps for a drug nanosuspension.


Nanosizing of drugs: Effect on dissolution rate.

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

The preparation steps for a drug nanosuspension.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: The preparation steps for a drug nanosuspension.
Mentions: Nanosuspensions contain colloidal dispersion of drug nanocrystals in a liquid dispersion medium such as water, aqueous solutions, or nonaqueous media which stabilized by surfactants and/or polymeric stabilizers (33780). Nanosuspension method is one of the promising methods in improving the dissolution rate of poorly-water soluble drugs. A nanosuspension not only can overcome the poor solubility and bioavailability of low water soluble drugs, but also could modify the pharmacokinetic profiles of drugs and thus improve their safety and efficacy (8182). Nanosuspensions are prepared by precipitation, high pressure homogenization, emulsion and milling techniques (8384). The particles in nanosuspensions are stabilized with mixture of surfactants or polymers (3885). Also by addition of a suitable tonicity modifier agent, the formulation may be used for intravenous injection. The formulations could also be further processed into standard dosage forms such as capsules and tablets for oral administration (40). Fig. 4 shows the preparation steps for a drug nanosuspension.

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.