Lakhasly

dialysis approach has been successfully used to generate tiny PNPs with a narrow size distribution (1) .A multi-tiered approach to preclinical characterization of nanomedicines involves physicochemical characterisation, sterility and pyrogenicity assessment, biodistribution, and toxicity characterization (12).d against a non-solventAkagi et al. used four organic solvents (DMSO, DMF, DMAc, and NMPy) to prepare PNPs from poly(?-glutamic acid) (PGGA)(3) They concluded that particles created with DMSO were smaller and had a narrower size dispersion than those prepared with NMPy.: The most prevalent supercritical fluid processing techniques include rapid expansion of supercritical solutions (RESS), the gas antisolvent process (GAS), the supercritical antisolvent process (SAS) and its different variations, and particles from gas-saturated solution (PGSS) processes (10).: In this regard, supercritical fluids (SCF) have emerged as an appealing alternative due to the use of environmentally benign technology, quick and reproducible scale up, good structural homogeneity control, and the creation of high purity nanomedicines(5) .Several experimental parameters might influence the shape and particle size distribution of the produced PNPs, including the sol-vent/non-solvent pair, dialysis MWCO, process temperature, polymer concentration, and solvent mixing speed [80].Typically, the polymer is dissolved in an organic solvent, inserted into the dialysis membrane, and dialyze : bASIC conditions include solvent miscibility and the presence of dilute polymer solutions.Jeong et al. employed a similar technique to create PLGA nanoparticles using DMAc, DMF, DMSO, and acetone as polymer solvents [82].: Supercritical carbon dioxide (scCO2) is the most commonly utilized SCF because it has mild critical conditions, is abundant, low-cost, non-flammable, non-toxic, and environmentally friendly(6).On the other hand, acetone produced bigger particles with an average size of 642 nm. This shift in particle size could be explained by differences in solvent viscosity, water miscibility, and polymer solubility.: supercritical fluid technologies The methods outlined in earlier sections require the use of organic solvents and surfactants, which are toxic to both the environment and physiological systems.In another study, Chronopoulou et al. investigated the effect of numerous experimental factors on the size and morphology of nanoparticles made from natural and synthetic polymers [80].Perrut and coworkers discussed the procedures employed to produce composite particles of poorly soluble active components (9).In addition, despite the availability of a variety of supercritical fluids, most polymers display low solubility or even non-solubility in supercritical fluids, which is the primary disadvantage of this technique.Although dialysis is a straightforward and frequent approach, the huge volume of counter dialyzing liquid may cause premature release of the nanoparticle payload due to the lengthy duration of the operation.For poly(methyl methacrylate) (PMMA) nanoparticles, a linear relationship between polymer content and nanosphere size was found.To tackle these challenges, research efforts have been dedicated toward developing ecologically friendly techniques for producing PNPs.In this approach, dialysis tubes or semipermeable membranes with an appropriate molecular weight cut-off (MWCO) serve as a physical barrier for the polymer(2) .3.

dialysis approach has been successfully used to generate tiny PNPs with a narrow size
distribution (1) . It is governed by a mechanism similar to the one described for the nanoprecipitation
technique, but with a slightly different experimental setup. In this approach, dialysis tubes or
semipermeable membranes with an appropriate molecular weight cut-off (MWCO) serve as a
physical barrier for the polymer(2) . Typically, the polymer is dissolved in an organic solvent, inserted
into the dialysis membrane, and dialyze : bASIC conditions include solvent miscibility and the
presence of dilute polymer solutions. The displacement of the solvent inside the membrane leads the
mixture to become increasingly less capable of dissolving the polymer. Furthermore, a rise in
interfacial tension causes polymer aggregation, which forms a colloidal suspension of nanoparticles.
Although dialysis is a straightforward and frequent approach, the huge volume of counter dialyzing
liquid may cause premature release of the nanoparticle payload due to the lengthy duration of the
operation.
Several experimental parameters might influence the shape and particle size distribution of the
produced PNPs, including the sol-vent/non-solvent pair, dialysis MWCO, process temperature,
polymer concentration, and solvent mixing speed [80]. Akagi et al. used four organic solvents (DMSO,
DMF, DMAc, and NMPy) to prepare PNPs from poly(γ-glutamic acid) (PGGA)(3)
They concluded that particles created with DMSO were smaller and had a narrower size dispersion
than those prepared with NMPy. Jeong et al. employed a similar technique to create PLGA
nanoparticles using DMAc, DMF, DMSO, and acetone as polymer solvents [82]. The size of the PNPs
made from DMAc, DMF, and DMSO ranged from 200 to 300 nm and did not differ considerably. On
the other hand, acetone produced bigger particles with an average size of 642 nm.
This shift in particle size could be explained by differences in solvent viscosity, water miscibility, and
polymer solubility. In another study, Chronopoulou et al. investigated the effect of numerous
experimental factors on the size and morphology of nanoparticles made from natural and synthetic
polymers [80]. For poly(methyl methacrylate) (PMMA) nanoparticles, a linear relationship between
polymer content and nanosphere size was found. The same behavior was seen with poly(phenyl
acetylene) (PPA) nanospheres.
Furthermore, at low concentrations, PPA nanoparticles with smaller diameters were formed at a
lower temperature than at ambient temperature. The effect of the MWCO was also investigated for
this synthetic polymer. It was demonstrated that decreasing the membrane MWCO causes a drop in
the mean particle size. The biopolymers under investigation likewise followed the similar pattern. This
is due to a decrease in the solvents' mixing rate, which favors thermodynamic effects over kinetic ones.
Changing the solvent/nonsolvent characteristics resulted in different morphologies for hyaluronic acid-
based nanostructures.
: supercritical fluid technologies The methods outlined in earlier sections require the use of organic
solvents and surfactants, which are toxic to both the environment and physiological systems.
However, if residual solvent impurities exist in drug-loaded PNPs, they can become toxic and destroy
the drug within the polymer matrix (4)]. There is also a hurdle in developing versatile and precise
nanomedicine production processes that can be easily scaled. To tackle these challenges, research
efforts have been dedicated toward developing ecologically friendly techniques for producing PNPs.
: In this regard, supercritical fluids (SCF) have emerged as an appealing alternative due to the use of
environmentally benign technology, quick and reproducible scale up, good structural homogeneity
control, and the creation of high purity nanomedicines(5) . A supercritical fluid (SCF) is one that has
been compressed and heated over its critical temperature (Tc) and pressure (Pc). Under such
conditions, its physicochemical properties are somewhere between gas and liquid. This is a new state
of matter in which the fluid behaves like a gas while having possessing the conventional density of a
liquid and consequently solvating properties(6) .
: Supercritical carbon dioxide (scCO2) is the most commonly utilized SCF because it has mild critical
conditions, is abundant, low-cost, non-flammable, non-toxic, and environmentally friendly(6). SCF
technique has received a great deal of attention in pharmacological research. There have been
numerous recent and outstanding studies published on pharmaceutical particle generation,
formulation, and control using a SCF. Fages et al. evaluated the approaches for producing particles
with SCF(7). Ginty et al. (8)described how SCF can be used to increase medication distribution. Perrut
and coworkers discussed the procedures employed to produce composite particles of poorly soluble
active components (9). Mishima et al. provided an overview of the creation of bi…
: The most prevalent supercritical fluid processing techniques include rapid expansion of
supercritical solutions (RESS), the gas antisolvent process (GAS), the supercritical antisolvent process
(SAS) and its different variations, and particles from gas-saturated solution (PGSS) processes (10).
These approaches are determined by the SCF's principal role, which is either solvent, solute, or
antisolvent. There is a large body of literature on employing SCF technology to produce drug-loaded
microparticles. Nanoparticles, on the other hand, have received far less research attention. The
implementation of supercritical fluid technology necessitates a significant investment in high-
pressure equipment.
In addition, despite the availability of a variety of supercritical fluids, most polymers display low
solubility or even non-solubility in supercritical fluids, which is the primary disadvantage of this
technique.
3. PNP Characterization Methods PNPs' use in pharmaceutical and biological applications has
revolutionized disease detection and therapy. Extensive characterisation of nanomaterials is critical
for preclinical research and any substantial improvements in their applications. There are currently
no established procedures or FDA regulatory protocols for characterizing nanoparticles(11) .
However, it is generally understood that physiological interactions are dependent on particle
physicochemical qualities. Creating a reasonably accurate image of the PNPs is critical for
understanding and predicting system performance in the body. A multi-tiered approach to preclinical
characterization of nanomedicines involves physicochemical characterisation, sterility and
pyrogenicity assessment, biodistribution, and toxicity characterization (12).d against a non-solvent