Nanosuspension: A Comprehensive Review  

Sayed Anasali Israrali¹*, Dr. Quazi Majaz Ahamad Aejazuddin, Abuzar Khan, Mansuri Jahid Siraj.

JIIU’s Ali Allana College of Pharmacy Akkalkuwa, Dist-Nandurbar -425415, Maharashtra, India

 

*Correspondence: aanas7385@gmail.com ; Tel.:(+918805093547)

Article Information		Abstract
Review Article Received: 25/12/2024 Accepted:  28/12/2024 Published: 01/01/2025   Keywords Nanosuspension, TYPES, Methods Of Preparation, Evaluation, Marketed products		Pharmaceutical formulations that employ nanosuspension technology to increase the solubility and bioavailability of poorly soluble medications are the main purpose of this review paper. A medication that is poorly soluble in water is suspended in a suitable dispersion medium stabilized by surfactants in nanosuspensions, which are sub-micron colloidal systems. This method is used because it offers advantages including improved pharmacokinetics, simplicity of administration, and versatility in dosage form design, while addressing problems like low bioavailability and solubility. Additionally, nanosuspensions offer important therapeutic benefits for a variety of drug administration routes, such as oral, parenteral, topical, ophthalmic, and pulmonary.

 

INTRODUCTION

A significant kind of pharmaceutical formulation, suspensions pose numerous difficulties for formula development staff due to their intrinsic structural instability as well as issues with manufacturing and packing. Suspensions may be intended for parenteral, external, or oral delivery. The continuous phase is usually made up of a finely split solid (individual particles with sizes ranging from 0.5 to 5.0μ) suspended in a liquid or semi-solid medium. Nowadays, a lot of suspensions are sold as dry powders, which are "constituted" prior to use by adding predetermined quantities of a vehicle. Stability issues are the primary reason for the production of such "suspensions."  A crucial factor in the formation of suspensions is the disperse phase's particle size. Topical suspensions should contain extremely fine particles to prevent a grainy feel during application and to give the region they are administered more coverage and protection. If the solid material is intended to penetrate the skin, its small size will accelerate the rate of dissolution and, consequently, the penetration. Particle sizes in suspensions intended for ocular cavity introduction shouldn't exceed 10μ. The suspension may cause pain or discomfort over this size, but below this, the patient has no pain. It is important for injectable suspensions to have particles that are small enough to fit through the syringe needle. Because they typically have a prolonged action, needle-shaped particles are preferred in "depot" type products. ^[1]

 

Types of suspensions:

 

1.According to the route of administration :

• Since oral suspensions are meant to be consumed orally, they need to have the right flavoring and sweetener.
• Since topical suspensions are intended for external use, they must be devoid of coarse particles.
• Parenteral suspensions should have the ability to be syringed and be sterile.
• Ophthalmic suspensions must to have extremely small particles and be sterile.

2. According to nature of dispersed phase and methods of preparation:

Suspensions that comprise diffusible solids, in-diffusible solids, weakly wet-table solids, precipitate-forming liquids, and chemical reaction products are all categorized.

3. According to nature of sediment:

Flocculated Suspensions:

In this kind, the solid particles in the dispersed phase group together to form a network-like structure in the dispersion medium. No firm cake is formed by the aggregates. since of their size, these aggregates settle quickly since the sedimentation rate is high and the silt that forms is loose and readily re-dispersible. Because the dispersed phase has a tendency to detach from the dispersion medium, the suspension lacks elegance. Therefore, controlled flocculation is preferred in order to maintain equilibrium between the rate of sedimentation, the kind of sediment generated, and the suspension's pourability.

Non flocculated Suspensions:

Solid particles of this kind exist in the dispersion medium as distinct entities. A firm cake is formed by the sediments. Since the rate of sedimentation is modest, the solid drug particles settle slowly, and redispersion becomes difficult as sediments finally accumulate. Because the scattered phase stays suspended for a long time, giving the suspension a uniform appearance, it is more elegant ^[1]. 

NANOSUPENSIONS:

The Greek word "nano" means "dwarf." A nano is one billionth, or a factor of 10-9. Furthermore, 40% of the novel chemical entities produced by drug discovery applications are lipophilic or poorly soluble in water. Pharmaceutical scientists typically find it challenging to formulate drugs that are poorly soluble in water.⁽²⁾

 A sub-micron colloidal system termed nanosuspension is made up of a medicine that is poorly soluble in water and is suspended in a compatible medium for dispersion that is stabilized by surfactants. Typically, inert colloidal carriers such as polymeric resins make up nanosuspensions. They aid in improving the solubility and, thus, the bioavailability of drugs. They are also well-liked due to the fact that they are not irritating, unlike microemulsions.^[3]
Because of its simplicity of administration, high patient compliance, cost-effectiveness, minimal sterility restrictions, and flexibility in dosage form design, the oral route is the most practical and widely used method for drug delivery. The main issue in designing oral dosage forms for about 50% of therapeutic compounds is their low bioavailability.^[4]

An developing discipline in all branches of science, engineering, and technology, nanotechnology is one of the most significant areas of research and development in contemporary science. It is a brand-new, all-encompassing field of study that blends the living sciences with medicine.^[4] By maintaining the medicine in the necessary crystalline form with smaller particles, nanosuspension technology speeds up the pace of dissolution. In addition to addressing the issues of low solubility and low bioavailability, nanosuspension modifies the drug's pharmacokinetics and enhances its efficacy and safety.^[4]

BENEFITS OF NANOSUSPENSIONS:

• Because of its broad application and ease of use, it can be beneficial for drugs that are not readily soluble in water.^[5]
• It may be converted into suitable dosage forms such tablets, capsules, pellets, hydro gel, and suppositories based on the formulator's requirements.⁽⁵⁾

• Tissue targeting and rapid disintegration are made possible by the intravenous route of delivery.⁽⁵⁾
• The administration of oral nanosuspensions results in a rapid onset, a decreased fed/fasted ratio, and improved bioavailability.

 • Drugs with high log P values can be made into nanosuspensions to improve their bioavailability. ⁽⁵⁾

• A shift in biological function brought on by excessive drug saturation and disintegration. ⁽⁵⁾

 • Batch-to-batch volatility is low and production procedures are straightforward.

• Less tissue irritation whether given intramuscularly or subcutaneously. ⁽⁵⁾

• A stronger propensity to stick, which enhances absorption.
• Site-specific distribution by surface modification of nanosuspension is a potential. ⁽⁵⁾

NEGATIVE ASPECTS OF NANOSUSPENSIONS:

• Physical instability, sedimentation, and compaction can all lead to issues. Because of its weight, handling and shipment need caution.
• When taken as prescribed, a consistent and accurate dosage cannot be given without suspension.^[5]
Applications:

1.      Topical formulations:

Using nanosuspensions in topical treatments with supersaturated structures (better solubility of saturation) enhanced drug diffusion pressure.^[2]

 

 

 

 

 

 

 

 

 

 

 

 

                  

                                                              Fig: For Topical formulation^[6]

2. Oral-cavity formulations (paste, gel, patches):

A.    A. Small particles enhanced adherence and prolonged residence for medications with inadequately high bioavailability in conventional oral formulations.

B.      As bio adhesion grew, inter-issue version decreased, dosage proportionality improved, and availability rose.^[2]

 

 

 

 

 

                                                       Fig: Gels for oral formulation ^[2]

 

 

 

 

 

 

                                                     Fig: Patches for oral formulation^[2]

 

3. Parentral Drug Delivery:

In addition, the parenteral medication delivery method makes use of nanotechnology. This method's benefit is that, for poorly soluble medicines, it requires considerably smaller amount of lethal cosolvent. When compared to the normal oral formulation and directing the medicine to the macrophages, this may increase the therapeutic impact of the medication. For the majority of the mycobacterium avium lines, the medicine clofazimine is administered intravenously (IV) when the concentration in the liver, spleen, and lungs reaches an excessive degree, or more than minimal inhibitory awareness. In order to improve the bioavailability, tarazepide is made as a nanosuspension rather than utilizing cyclodextrins and surfactants.^[2]

 

 

 

 

 

 

Fig: IV for parentral drug delivery^[2]

 

4. Ocular delivery:

Compared to traditional ocular dosage forms, nanosuspension of nanoparticles (NPs) has several advantages, such as lower dosage, sustained drug release over an extended period of time, decreased systemic toxicity, improved drug absorption because of the nanoparticles' longer residence time on the corneal surface, higher drug concentrations in the infected tissue, and suitability for poorly water-soluble drugs. Additionally, patients tolerate smaller particles better than larger ones, which suggests that nanoparticles may be auspicious drug carriers for ophthalmic applications.^[6]

 

 

 

 

 

 

 

Fig: For ocular drug delivery^[6]

5. Pulmonary:

Drugs that are poorly soluble in pulmonary secretions may benefit from delivery using nanosuspensions. Current methods of pulmonary administration, including aerosols or dry powder inhalers, have a number of drawbacks, such as limited diffusion at the desired location, a shorter residence period, and many more, which can be overcome with nanosuspensions. Budesonide and fluticasone had been effectively combined to create a nanosuspension for pulmonary administration.^[2]

  

                                                   Fig: For pulmonary drug delivery^[2]

6. Mucoadhesion of Nanoparticle:

When the nano suspension is consumed orally, it forms a liquid medium and sticks to the mucosal surface before being absorbed. It enhances bioavailability and targets the parasite that is causing the git to persist. Such as buparvaquone inhibits Cryptosporidiparvum.^[2]

 

 

 

 

 

 

Fig: Mucoadhesive nanoparticals ^[2]

 

 

 

     

                                         Fig: Methods for preparation of Nanosuspension^[7]

Method of preparation of Nanosuspension:

TECHNIQUES FOR PREPARATION OF NANOSUSPENSIONS:^[7]

Although theoretically easier than liposomes and other traditional colloidal drug carriers, nanosuspensions are said to be more economical. It is especially used for medications that are poorly soluble and to produce a product that is more physically stable. There are two opposite approaches for producing nanosuspensions: "Bottom-up process technology" and "Top-down process technology." From huge particles to microparticles to nanosized particles, the top-down method employs a disintegration technique. High pressure homogenization, media milling (nanocrystals), nanoedge, and nanopure are a few examples.
Using a bottom-up approach, molecules are assembled into nanoparticles. Among the examples are Method of Solvent-Antisolvent Extremely important fluid process Emulsification Method of Solvent Evaporation Template for lipid emulsion or micro-emulsion. The following are the main methods for creating nanosuspensions that have been employed recently:

1.Top-down process technology:

A.HIGH PRESSURE HOMOGENIZATION:

It is the most popular technique for creating nanosuspensions of several medications that are not very soluble in water. There are three steps involved. Pre-suspension is created by first dispersing drug powders in stabilizer solution, then homogenizing the pre-suspension at low pressure for pre-milling in a high pressure homogenizer, and finally homogenizing at high pressure for 10 to 25 cycles to create nanosuspensions of the appropriate size. This idea has led to the development of several techniques for creating nanosuspensions, including Disso-cubes, Nano pure, Nano edge, and Nano jet.^[7]

 

 

 

Homogenization in aqueous media (Disso cubes):

Using a piston-gap type high pressure homogenizer, R.H. Muller invented this method in 1999. This technique uses a high pressure homogenizer with a nanosized aperture valve to drive a drug and surfactant solution through it under pressure.

Principle:

The cavitation theory is the foundation of this technique. The dispersion in a cylinder with a diameter of 3 cm is abruptly forced through a 25µm thin opening.Bernoulli's law states that a closed system's liquid flow volume per cross section is constant. Because the diameter is reduced from 3 cm to 25 µm, dynamic pressure rises while static pressure falls below the room temperature boiling point of water.At room temperature, the water then begins to boil and produces gas bubbles, which burst as the suspension exits the gap (a process known as cavitation) and the air pressure returns to normal. The cavitation forces of the particles are significant enough to transform the drug microparticles into nanoparticles.

Advantages:

1. It prevents treated materials from eroding.
2. It works with medications that don't dissolve well in organic or aqueous solutions.

Disadvantages:

1. Preliminary processing, such as  micronization, is necessary.
2. The need for expensive equipment raises the price of the dosage form.

Homogenization in nonaqueous media (Nanopure):

Suspensions homogenized in water-free medium or water mixes, such as PEG 400, PEG 1000, etc., are known as nanopure. It is referred to as "deep freeze" homogenization because it may be carried out at ambient temperature, 00°C, and below the freezing point (-200°C).^[7]

Nanoedge:

The simultaneous process of precipitation and homogenization is known as nanoedge technology. The fundamental idea is the same as that of homogenization and precipitation. The Nanoedge technology may be used to solve the main drawbacks of the precipitation process, including crystal development and long-term stability. It is possible to produce particles with improved stability and reduced size quickly.^[7]

Nanojet:

Also known as opposite stream technology, it employs a chamber to split a stream of suspension into two or more sections that merge at high pressure. Because of the tremendous shear forces created during the operation, the particle size is decreased.^[7]

 

 

 

 

B.MILLING TECHNIQUES:

I ) Media Milling:

Liversidge (1992) was the first to create and report on this strategy. This approach uses a high shear media mill to prepare the nanosuspensions. The milling chamber revolved at a very high shear rate for at least two to seven days at a regulated temperature after being loaded with the milling medium, water, medication, and stabilizer. Glass, zirconium oxide, or strongly cross-linked polystyrene resin make up the milling media. The drug is impacted with the milling media, causing the drug's microparticles to split into nanoparticles and creating high energy shear pressures. ^[7]

 Advantages:

1. Drug quantities ranging from 1 mg/ml to 400 mg/ml can be used to create both extremely diluted and highly concentrated nanosuspensions.
2. The final nanosized product's dispersion at the nanoscale.

Disadvantages:

1. The process of media milling takes a lot of time.
2. A small percentage of particles are micrometers in size.
3. The size and weight of the mill make scaling up difficult.

II) Dry-Co-grinding:

A lot of nanosuspensions are now made using the dry milling process. Dry-cogrinding is a simple, cost-effective process that doesn't use organic solvents. Co-grinding improves the surface polarity and changes a crystalline medication into an amorphous one, which improves the physicochemical characteristics and dissolving of poorly water soluble medicines. ^[7]

Advantages

1.      The method is simple and doesn't require an organic solvent.

2.       Need little time to grind.

Disadvantages:

1. Production of milling media residue.

C. EMULSIFICATION-SOLVENT EVAPORATION TECHNIQUE:

This method entails making a drug solution and then emulsifying it in a different liquid that isn't a solvent for the medication. The substance precipitates as the solvent evaporates. A high-speed stirrer may be used to generate strong shear forces, which will regulate crystal development and particle aggregation. ^[7]

D. PRECIPITATION:

Precipitation has been used in the past ten years to create submicron particles, particularly for medications that are not readily soluble. Prior to being combined with a miscible antisolvent in the presence of surfactants, the medication is first dissolved in a solvent. When a drug solution is quickly added to the antisolvent, the drug becomes suddenly super-saturated and forms ultrafine crystalline or amorphous drug solids. ^[7]

Benefits:

 Include economical production, ease of scaling up, and a straightforward procedure.
Drawbacks:

The inclusion of a surfactant is necessary to restrict the growth of crystals.
The drug has to dissolve in at least one solvent.

E. SUPERCRITICAL FLUID PROCESS:

The technologies of solubilization and nanosizing using the super critical fluid process were able to reduce the particle size considerably. Supercritical fluids (SCF) are thick, noncondensable fluids with temperatures and pressures higher than their critical values (Tc and Tp).Drug particles can be micronized to the submicron level with this method. Recent developments in the SCF method have made it possible to produce nanoparticulate suspensions with diameters ranging from 5 to 2000 nm. This technology's use in the pharmaceutical sector is limited by the high pressure needed for these procedures and the low solubility of weakly water-soluble medications and surfactants in supercritical CO2. ^[7]

F. MELT EMULSIFICATION METHOD:

This approach creates an emulsion by dispersing the drug in the stabilizer's aqueous solution, heating it over the drug's melting point, and homogenizing it. In order to keep the emulsion's temperature above the drug's melting point, the sample holder was wrapped in a heating tape that had a temperature controller attached. The emulsion was subsequently chilled on an ice bath or gradually to room temperature. ^[7]

Advantages: In contrast to the solvent evaporation method, the melt emulsification approach completely eliminates the use of organic solvents in the manufacturing process.

Disadvantages: Compared to solvent evaporation, there are less compliant objects and bigger particles formed.

G. LIPID EMULSION/MICROEMULSION TEMPLATE:

This method works effectively for drugs that dissolve in volatile organic solvents or partially water miscible solvents. In this procedure, the medication is dissolved in a suitable organic solvent and then emulsified in an aqueous phase using suitable surfactants. The organic solvent was then gradually evaporated under reduced pressure to produce drug particles that precipitated in the aqueous phase and created the aqueous suspension of the drug in the required particle size. Nanosuspensions can then be made by suitably diluting the resultant suspension. Additionally, microemulsions can be used as templates to make nanosuspensions. An interfacial layer of surfactant

and co-surfactant stabilizes the thermodynamic stability and isotropic clarity of microemulsions, which are dispersions of two immiscible liquids, such as water and oil. Either the drug is placed into the internal phase or the drug is intimately mixed into the pre-formed microemulsion to make it saturated. The drug nanosuspension is produced by appropriately diluting the microemulsion. Lipid emulsions are useful as templates for the generation of nanosuspensions because they are simple to make by regulating the emulsion droplet and are simple to scale up. However, using organic solvents has an adverse effect on the environment, and a lot of stabilizer or surfactant is needed. ^[7]

 

Advantages :

High drug solubilization

1. Extended shelf life
2. Simple to produce.

Disadvantages:

1. Hazardous solvent use
2. A lot of stabilizers and surfactants are used.

H. SOLVENT EVAPORATION:

The solvent evaporation method creates polymer solutions in emulsions and volatile solvents. However, the usage of dichloromethane and chloroform in previous years has been replaced with ethyl acetate, which has a superior toxicological profile. When the solvent for the polymer evaporates, the emulsion transforms into a suspension of nanoparticles that can permeate the continuous phase of the emulsion. One of the two primary approaches utilized in conventional procedures for emulsion production is the creation of single emulsions, such as oil-in-water (o/w), or double emulsions, such as (w/o)/w. The solvent must be evaporating using continuous magnetic stirring at ambient temperature or at decreased pressure after high-speed homogenization or ultrasonication. After being collected by ultracentrifugation, the solidified nanoparticles were lyophilized after being cleaned of additives like surfactants using distilled water. The polymer concentration, stabilizer, and homogenizer speed all had an impact on the particle size.^[7]

2.BOTTOM-UP PROCESS:

Increasing particle size from the molecular to the nanoscale area is one method of reaching nanosize. The term "bottom-up technique" describes the traditional "hydrosol" or precipitation procedures. The precipitation method is used to dissolve the drug in an organic solvent, and the resultant solution is mixed with a miscible anti-solvent. The drug's poor solubility in the water-solvent combination causes it to precipitate. The primary problem is that the crystal growth needs to be controlled by adding surfactant in order to stop the formation of microparticles during the precipitation process. ^[5]

Advantages:

1. Using basic and affordable equipment

2. One advantage of precipitation over other nanosuspension guiding methods is its higher saturation solubility. ^[5]

Disadvantages:

1Drugs that are not adequately soluble in fluid and non-watery conditions are no longer present in precipitation systems. In this system, the medication should dissolve in at least one dissolvable that is miscible with the non-solvent^[5].

2. Prevent Ostwald ripening, which is brought on by unique saturation solubilities close to particles of varying sizes, from causing crystal formation.^[5]

 

PRECIPITATION METHOD:

One common technique for creating poorly soluble submicron drug particles is precipitation. In this technique, the medication is dissolved in a solvent before the solution is added to the solvent, which at first the drug cannot dissolve in. The drug rapidly becomes supersaturated in the solution and creates an ultrafine amorphous or crystalline drug when the solution is swiftly added to a solvent, usually water. Both crystal growth and nucleus formation, which are mostly temperature-dependent processes, are involved in this process. Low crystal growth rate and high nucleation rate are necessary to produce a stable solution with tiny particles.^[5]

 

 

 

 

 

 

 

 

 

 

                                        Fig: Schematic representation of precipitation method^[5]

Evaluation methods for Nanosuspension:

1. In-vitro evaluation:

1. Particle size and size distribution

2. Particle charge (Zeta Potential)

3. Crystalline state and morphology

4. Saturation solubility and dissolution velocity.

5. Density

6. ph value

7. Droplet size

8. viscosity measurement

9. Stability of nanosuspension

2. In-vivo evaluation

3. Evaluation for surface-modified nanosuspension:

1. Surface hydrophilicity

2. Adhesion properties

3. Interaction with body proteins.

4. Quality assurance

5. In process quality control

1. In-vitro evaluation:

1. Mean particle size and size distribution:

Photon Correlation Spectroscopy (PCS) is used to estimate the average size of the particles and the breadth of the variation in particle size, also known as the Polydispersity Index. The polydispersity index (PI) and particle size control the biological performance, dissolving rate, and saturation solubility. It has been demonstrated that variations in particle size alter dissolving velocity and saturation solubility. PCS only monitors particle sizes between 3 nm and 3 μm. Although PCS is a flexible method, its measurement range is limited. Laser Diffractometry (LD) is used to study nanosuspensions in addition to PCS analysis. ^[8]

2. Particle charge (zeta potential):

Determining a nanosuspension's zeta potential is vital because it provides insight into how the medication and stabilizer interact to control the suspension's potential. An electrostatically stabilized nanosuspension requires an ideal zeta potential of 30 mV to provide adequate stability, while a mixed electrostatic and 20 mV nanosuspension is preferred.^[8]

3. Crystalline state and particle morphology:

Assessing the amount of an amorphous drug's change in physical state is a different application for X-Ray Diffraction (XRD). The crystalline structure is ascertained by Differential Scanning Calorimetry (DSC). Measuring the amount of amorphous drug produced during the creation of nanosuspensions is crucial since drug particles change into an amorphous state as they are made.^[8]

4. Solubility and Dissolution velocity :

Enhanced saturated state solubility and dissolving velocity are the primary benefits of nanosuspensions. They are investigated at varying pH levels in various physiological solutions. Increases in saturation solubility can be explained by the Kelvin equation and the Ostwald-Freundlich equations. Determining these metrics helps evaluate the formulation's performance in vivo.^[8]

5. Density:

One crucial factor is the formulation's specified gravity or volume. The existence of trapped air inside the formulation's structure is frequently indicated by a drop in volume. It is important to use a homogeneous, well-mixed formulation when measuring volume at a certain temperature; a precision hydrometer makes this easier.^[9]

 

 6. pH Value:

To reduce "pH drift" and electrode surface coating with suspended particles, the pH value of the aqueous formulation should be measured at a certain temperature and only when settling equilibrium has been attained. To stabilize the pH, electrolyte shouldn't be introduced to the formulation's exterior phase.^[9]

 7. Droplet Size:

Either electron microscopy or the light scattering approach can be used to determine the droplet size distribution of micro emulsion vesicles. dynamic light scattering spectrophotometer that use a 632 nm-wavelength neon laser.^[9]

 8. Viscosity Measurement:

A Brookfield type rotating viscometer may be used to evaluate the viscosity of lipid-based formulations of various compositions at various shear rates and temperatures. The samples for the measurement must be submerged in a thermobath that keeps the instrument's sample chamber at 37⁰ C. ^[9]

 9. Stability of Nanosuspension:

The drug crystals aggregate due to the high surface energy of the nanoparticles. By creating a steric or ionic barrier, the stabilizer's primary job is to completely soak the drug molecules in order to stop Ostwald ripening and agglomeration of the Nanosuspension and create a formulation that is physically stable. Stabilizers that are commonly employed in nanosuspensions include lecithin, polyoleate, poloxamer, cellulosics, and povidones. When creating parenteral nanosuspensions, lecithin can be the better option.^[9]

2. In-Vivo Biological Performance:

Establishing an in-vitro/in-vivo connection and monitoring the drug's efficacy in vivo are essential study components, regardless of the route and administration mechanism employed. In the case of intravenously administered nanosuspensions, it is crucial since the drug's in-vivo behavior is dependent on the distribution of its organs, which depends on its hydrophobicity and interactions with plasma proteins, among other surface properties. In actuality, the key element influencing organ distribution is acknowledged to be the qualitative and quantitative makeup of the protein absorption pattern seen following intravenous injection of nanoparticles. Therefore, appropriate methods must be employed to assess the surface characteristics and protein interactions in order to get insight into invivo behavior. Surface hydrophobicity may be assessed using methods like hydrophobic interaction chromatography, whereas 2-D PAGE can be used to detect protein adsorption both quantitatively and qualitatively following intravenous administration of drug nanosuspensions in animals.^[10]

The medication and delivery method are particular to the in vivo assessment of the nanosuspensions. Typically, the medication was administered by the prescribed method, and HPLC-UV visible Spectrophotometry was used to measure the drug in the plasma levels.^[8]

3.Quality Assurance (QA):

A wide range of elements that either separately or in combination impact a product's quality are taken into account by the broad notion of quality assurance. In order to guarantee the proper quality of the finished product, this method critically examines what has happened yesterday, what is occurring today, and what will happen tomorrow. A minor subset of quality assurance, quality control (QC) deals with sampling, testing, and documenting both during and after manufacture. To guarantee a high-quality product each and every time, quality control is the monitoring process by which manufacturers measure actual quality performance, compare it to standards, and address the reasons for deviations from standards. Based on its purpose, a quality control system can be separated into two sections: final quality control and in-process quality control.^[11]

4. In Process Quality Control (IPQC):

Suspensions' Ipqc Process quality control involves keeping an eye on important manufacturing process variables to guarantee the end product's quality and to provide the required guidance in the event that a difference is discovered. To guarantee that a predictable portion of each output cycle falls within the acceptable standard range, quality control and production staff create and document controls in process manufacturing. The following has to be specified in order for in-process quality control to operate properly.Which procedure has to be watched, and when? How many samples should be collected for analysis, and how often should they be taken? Each sample's quantitative quantities, allowable fluctuation, etc.^[11]

Marketed products of Nanosuspension: ^[12]

Trade name/company	Drug	Dosage form	Nanosuspension method	Indication
Abraxane®/Abraxia Biosciences	paclitaxel	Freeze dried powder for inj.	NabTM	Metastatic breast cancer
Cesamet®	Lilly Nabilone	Capsule	Co-precipitation	Antiemetic
Emend®/Merck	Aprepiant	Capsule	Nanocrystal®Elan Nanosystems	Antiemetic
Giris-PEG® /Novartis	Griseofulvin	Tablet/Oral	Coprecipittation	antifungal
Invega Sustenna®/ Johnson & Johnson	Palperidone palmitate	Liquid nanosuspension	High pressure homogenization	Schizophrenia
Rapammune®/Wyeth	Sirolimus	Tablet	Nanocrystal®Elan Nanosystems	Immunosuppressant
Tricor®/Abbott	Fenofibrate	Tablet	Nanocrystal®Elan Nanosystems	Hypercholesterolemia

 

Technology and Patent for Nanosuspension:^[12]

CONCLUSION:

Drugs that are hydrophobic or poorly soluble in organic and aqueous solvents can have their low solubility and bioavailability issues resolved commercially by nanosuspension. The modes of administration for nanosuspensions include oral, parenteral, pulmonary, ophthalmic, and topical. A nanosuspension changes the drug's pharmacokinetics, improving its safety and effectiveness while also improving the drug's solubility, bioavailability, and absorption. Its therapeutic benefits include a straightforward preparation process, a lower need for excipients, and an improvement in the drug's dissolving rate and saturation solubility. As oral formulations and non-oral administration advance, nanosuspensions will remain of interest due to their numerous uses, easy production technologies, and drug delivery capabilities.

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