I am a little confuse with the mechanism of solid lipid nanoparticles (SLNs). The main point of encapsulating drugs into SLNs is because some drugs have low solubility in water. Therefore, SLNs works as a drug carrier which it is also known to be soluble in our blood.
If the drug is water insoluble, this means it cannot be dissolved in water. In this case, we need to melt the drug and mix it with lipid (heat them above 5 - 10 C of the lipid melting temperature) and then, mix them with the aqueous solution (surfactant + water). Hence, we will have an emulsion.
Was wondering, what is the state of the drug (eg: drug is solid at room temperature), if the melting point of the drug is higher (for instance 200 C) than the melting points of lipid (70 C) and surfactant used? Is it dissolve in the fluid or is it a dispersion?
As the mane suggest, the drug is in solid form, as crystalline of amorphous. Reducing particle size helps dissolution, amorphous helps permeability; however, the amorphous form it needs to be stabilized. Ultimately the challenge is the particle size reduction in the micron/nano range for the crystalline form and/or amorphous stabilization against polymorph transformation and degradation. The SLN does the delivery part.
The drug will be in dispersed state, more clearly in solid form along with the lipid During the formulation of SLN, the drug-lipid matrix forms due to melting. In this melted state, the insoluble solid particles are reduced in size and shape attaining an amorphous or crystalline (if the drug doesnot melt at the temperature provided while lipid melts). The drug may attain a thermodynamic stability during the melting process.
Thus the chances of improving the solubility will be higher.
- Badges
- Science topic