Formulation and evaluation of docetaxel nanosuspensions: In-vitro evaluation and cytotoxicity

Formulation and evaluation of Fluconazole Nanosuspensions: In vitro characterization and transcorneal permeability studies

The aim in this study was to develop and evaluate a nanofluconazole (FLZ) formulation with increased solubility and permeation rate using nanosuspensions. The FLZ nanosuspensions were stabilized using a variety of stabilizing agents and surfactants in various concentrations. The FLZ nanosuspension was characterized in vitro using particle size, zeta potential, X-ray powder diffraction (XRPD), and solubility. In addition, the ex vivo ocular permeation of FLZ through a goat cornea was analyzed. The results showed that the particle size of all nanosuspension formulations was in the nanometer range from 174.5 ± 1.9 to 720.2 ± 4.77 nm; that of the untreated drug was 18.34 μm. The zeta potential values were acceptable, which indicated suitable stability for formulations. The solubility of the nanosuspensions was up to 5.7-fold higher compared with that of the untreated drug. The results of the ex vivo ocular diffusion of the FLZ nanosuspensions showed the percentage of FLZ penetrating via the goat cornea increased after using Kollicoat to stabilize the nanosuspension formulation. Consequently, when using a nanosuspension formulation of Kollicoat, the antifungal activity of the drug strengthens.

Biophysical characterization of siRNA-loaded lipid nanoparticles with different PEG content in an aqueous system

Although lipid nanoparticles (LNP) are potential carriers of various pharmaceutical ingredients, further investigation for maintaining their stability under various environmental stressors must be performed. This study evaluated the influence of PEGylation and stress conditions on the stability of siRNA-loaded LNPs with different concentrations of PEG (0.5 mol%; 0.5 % PEG-LNP and 1.0 mol%; 1.0 % PEG-LNP) anchored to their surface. We applied end-over-end agitation, elevated temperature, and repeated freeze and thaw (F/T) cycles as physicochemical stressors of pH and ionic strength. Dynamic light scattering (DLS), flow imaging microscopy (FIM), and ionic-exchange chromatography (IEX) were to determine the degree of aggregation and change in siRNA content. The results indicate that 0.5 % PEG-LNP resisted aggregation only at low pH levels or with salt, whereas 1.0 % PEG-LNP had increased colloidal stability except at pH 4. 0.5 % PEG-LNP withstood aggregation until 71 °C and three cycles of F/T. In contrast, 1.0 % PEG-LNP maintained colloidal stability at 90 °C and seven F/T cycles. Moreover, 1.0 % PEG-LNP had higher siRNA stability under all stress conditions. Therefore, to ensure the stability of LNP and encapsulated siRNA, the PEG concentration must be carefully controlled while considering LNPs' colloidal instability mechanisms under various stress conditions.

Surface-modified nanoparticles of docetaxel for chemotherapy of lung cancer: An intravenous to oral switch

Despite being potent, the marketed formulations of Docetaxel (DX) are associated with numerous side effects and are meant for intravenous administration. Advanced pharmaceutical nanotechnology has a significant potential to facilitate the 'intravenous (i.v) to oral switch'. The present research work deals with the development of an orally administrable, folate-receptor-targeted Nanostructured lipid carriers (NLCs) of DX (FA-DX-NLCs) for facilitating oral chemotherapy of lung cancer while overcoming the bioavailability and toxicity issues. The nanoformulation prepared to employ high-pressure homogenization and lyophilization, was evaluated and statistically analyzed for various in-vitro and in-vivo formulation characteristics. The lyophilized nanoparticles were observed to be spherical with a particle size of 183.4 ± 2.13 (D90), Pdi of 0.358 ± 0.03, % EE of 82.41 ± 2.44, % DL of 4.41 ± 0.54 and a zeta potential of -3.3 ± 0.7 mv. The increased oral in-vivo bioavailability of DX was evident from the plasma-concentration area under the time curve (AUC_0-t), which was ∼ 27-fold greater for FA-DX-NLCs as compared to DX suspension. The orally administered FA-DX-NLCs exhibited excellent antitumor efficacy in a pre-clinical model of lung carcinoma. Tumor staging, histopathology, and immunostaining of the tumors suggested greater anti-proliferative, apoptotic, anti-metastatic, and anti-angiogenic potential as compared to DX-suspension. The pre-clinical toxicity studies affirmed the excellent safety and bio-compatibility of FA-DX-NLCs. The research work presents immense translational potential for switching the DX-based chemotherapy for lung cancer from 'hospital to home.'

Development of nanoemulsion of antiviral drug for brain targeting in the treatment of neuro-AIDS

Background

Delivery of drugs via the nasal route directly to the brain utilizing the olfactory pathway is purportedly known to be a more efficient method to deliver neuro-therapeutics to the brain by circumventing the BBB, thereby increasing the bioavailability of these drugs in the brain. The main objective of the project work is to improve the bioavailability of the antiretroviral drug and to minimize the side effects of this therapy which are observed at the higher side in the chronic HIV treatment. The advantage of nasal drug delivery is its noninvasiveness and self-administration. Nanoformulation provides fast onset of action and helps to achieve site-specific delivery. In the current work, nanoemulsion formulation was developed with a ternary phase system. In vitro characterization of nanoemulsion was performed.

Result

Optimized batch B2 had a zeta potential of − 18.7 mV showing a stable emulsion system and a particle size of 156.2 nmin desirable size range. Batch B2 has the least variation in globule size with PDI 0.463. Results from ex vivo studies revealed that developed nanoemulsion (B2) possessed a higher rate of drug release compared to other formulations.

Conclusion

Phase diagrams indicated more width of the nanoemulsion region with an increase in surfactant ratio. Stable nanoemulsion was prepared with a combination of surfactant and co-surfactants. Nanoemulsions could prove one of the best alternatives for brain delivery of potent medications.

Graphical Abstract

Ambroxol Hydrochloride Loaded Gastro-Retentive Nanosuspension Gels Potentiate Anticancer Activity in Lung Cancer (A549) Cells

This study aimed to develop gastro-retentive sustained-release ambroxol (ABX) nanosuspensions utilizing ambroxol-kappa-carrageenan (ABX-CRG_K) complexation formulations. The complex was characterized by differential scanning calorimetry, powder x-ray diffractometer, and scanning electron microscopy. The prepared co-precipitate complex was used for the development of the sustained-release formulation to overcome the high metabolic and poor solubility problems associated with ABX. Furthermore, the co-precipitate complex was formulated as a suspension in an aqueous floating gel-forming vehicle of sodium alginate with chitosan, which might be beneficial for targeting the stomach as a good absorption site for ABX. The suspension exhibited rapid floating gel behaviour for more than 8 h, thus confirming the gastro-retentive effects. Particle size analysis revealed that the optimum nanosuspension (ABX-NS) had a mean particle size of 332.3 nm. Afterward, the ABX released by the nanoparticles would be distributed to the pulmonary tissue as previously described. Based on extensive pulmonary distribution, the developed nanosuspension-released ABX nanoparticles showed significant cytotoxic enhancement compared to free ABX in A549 lung cancer cells. However, a significant loss of mitochondrial membrane potential (MMP) also occurred. The level of caspase-3 was the highest in the ABX-NS-released particle-treated samples, with a value of 416.6 ± 9.11 pg/mL. Meanwhile, the levels of nuclear factor kappa beta, interleukins 6 and 1 beta, and tumour necrosis alpha (NF-kB, IL-6, IL-1β, and TNF-α, respectively) were lower for ABX-NS compared to free ABX (p < 0.05). In caspase-3, Bax, and p53, levels significantly increased in the presence of ABX-NS compared to free ABX. Overall, ABX-NS produced an enhancement of the anticancer effects of ABX on the A549 cells, and the developed sustained-release gel was successful in providing a gastro-retentive effect.

Preparation and Characterization of Docetaxel-PLGA Nanoparticles Coated with Folic Acid-chitosan Conjugate for Cancer Treatment

The conjugation of chitosan (CS) and folic acid (FA) was prepared and used to coat PLGA nanoparticles (NPs) that are loaded with Docetaxel (DTX) to target cancer cells that have lower pH and overexpression of folate receptors in comparison to normal cells. Three formulations had been prepared to reach the highest loading capacity (LC%) and encapsulation efficiency (EE%) and to study the effect of the amount of FA-CS on the drug release. The sizes, charges, homogeneity, surface morphology, LC% and EE% of the NPs were determined. The NPs were characterized using FTIR and XRD. In vitro release profiles of DTX from PLGA NPs, at pH 5.5 and 7.4 were determined. Finally, in vitro cytotoxicity assay on three cancer cell lines (RPMI 2650, Calu-3, and A549) was studied. The sizes of the three formulations ranged between 250.3±1.7 and 356.3±17.7. All prepared formulations showed acceptable monodispersity with highly positive charges. The EE% was above 85% and the LC% ranged between 6-35%. The in vitro release of DTX show an inverse relation to the amounts of FA-CS used and the pH of the dissolution medium. Coated PLGA NPs showed a significant difference in RPMI 2650, Calu-3, and A549 cell viability in comparison to free DTX. The NPs components were safe and non-toxic to human cells. In conclusion, coating PLGA NPs with FA-CS may be used as a good carrier for chemotherapeutic agents that selectively target carcinogenic tissues.

Improved transdermal permeability of tanshinone IIA from cataplasms by loading onto nanocrystals and porous silica

Novel transdermal cataplasms have been designed to improve permeability of poorly soluble drugs by different pretreatments. Nanocrystal and porous silica solid dispersions were loaded with Tanshinone IIA and incorporated into a cross-linked hydrogel matrix of cataplasm. It was shown that the small particle size and improved dissolution would increase dermal bioavailability. The adhesion, rheological properties, drug release, skin permeation, skin deposition and in vivo skin absorption of the different formulations were investigated. In an in vitro experiment using mouse skin, cumulative amount of drug permeated within 24 h was 7.32 ± 0.98 μg/cm² from conventional cataplasm, 13.14 ± 0.70 μg/cm² from nanocrystal-loaded cataplasm and 11.40 ± 0.13 μg/cm² from porous silica solid dispersion-loaded cataplasm. In vitro dissolution profiles showed that drug release was 76.5% and 74.9% from two optimized cataplasms within 24 h, while conventional cataplasm was 55.0%. The cross-linking characteristics of the cataplasms were preserved after incorporation of different drug forms, while the elastic and viscous behaviors of the hydrogel layers increased. In vivo evaluation by CLSM showed the more favorable skin permeation for two optimized cataplasms. These findings suggest that applications of nanocrystal and porous silica systems on cataplasms enable effective transdermal delivery of poorly soluble drugs. The resulting drug delivery and rheological properties are desirable for transdermal application.AbbreviationAll the abbreviations that appear in this article are shown in Table 1.

Fluconazole nanoparticles prepared by antisolvent precipitation technique: Physicochemical, in vitro, ex vivo and in vivo ocular evaluation

The goal of this research was to prepare and characterize nanonized particles of the antifungal drug, fluconazole (FLZ) using antisolvent precipitation nanonization technique to improve its ocular permeation. The impact of various concentrations of different stabilizers, namely Pluronic F-127 (PL F 127), Kollicoat IR (KL), hydroxypropyl methylcellulose E3 (HPMC), xanthan gum (XG), polyvinyl pyrrolidone K30 (PVP), and sodium lauryl sulfate (SLS) upon the resulting nanoparticles was investigated. Additionally, the ex vivo release of the FLZ nanonized particles from ophthalmic gel bases was studied by using goat cornea, and the ocular pharmacokinetics of appropriate ophthalmic gel base containing optimized drug nanoparticle formula compared to the untreated drug were studied in rabbits. FLZ nanoparticles were successfully prepared with different concentrations of stabilizers. However, the effects of these stabilizers on nanoparticle size and zeta potential values varied according to the concentration and type of stabilizer used. Based on differential scanning calorimetry, the drug was in its amorphous state in the tested nanoparticle formulations. The results of ex vivo ocular diffusion of the FLZ nanoparticle gel formulations revealed an improvement compared to that with the FLZ untreated gel. Nanoparticle formula (F3) prepared by using 5% PL F127 showed small particle size (352 ± 6.1 nm) with zeta potential value of −18.3 mV with highest ex vivo release rate from goat cornea (100% after 6 h). Moreover, the AUC_0-8h from ocular application of FLZ from sodium alginate gel containing nanoparticle formula F3 was 1.4-fold higher than that after its administration in the untreated formula. Based on our findings, the ophthalmic gel formulations containing FLZ nanoparticles enhanced drug corneal permeation and improved the ocular pharmacokinetic parameters.

Development of Polymer and Surfactant Based Naringenin Nanosuspension for Improvement of Stability, Antioxidant, and Antitumour Activity

Nanosuspensions are widely reported to enhance the solubility of poorly soluble drugs. In addition to enhancement in solubility, improvement of stability and therapeutic efficacy would be an added advantage. In the present study, premilling and subsequent high-pressure homogenization were carried out to produce naringenin nanosuspension. Hydroxypropyl methylcellulose and sodium dodecyl sulfate were evaluated for their performance as stabilizers under various homogenization cycles. The prepared nanosuspensions were studied for average particle size and size distribution, zeta potential, solubility, drug release, antioxidant activity, and in vitro antitumor activity. It was observed that both hydroxypropyl methylcellulose-stabilized nanosuspension and sodium dodecyl sulfate-stabilized nanosuspension produced an enhancement in physical stability, antioxidant potential, and in vitro cytotoxicity compared with naringenin. Furthermore, hydroxypropyl methylcellulose-stabilized nanosuspension was found to be better than sodium dodecyl sulfate-stabilized nanosuspension in terms of particle size and size distribution, storage stability, and drug release. This study showed that nanosuspension formulations could be a potential strategy for improving dissolution and antitumor activity of naringenin.

Investigation of Formulation and Process Parameters of Wet Media Milling to Develop Etodolac Nanosuspensions

PURPOSE

Etodolac (ETD) is one of the non-steroidal anti-inflammatory drugs which has low aqueous solubility issues. The objective of this study was to develop ETD nanosuspensions to improve its poor aqueous solubility properties while investigating formulation and process parameters of wet media milling method via design of experiment (DoE) approach.

METHODS

The critical formulation parameters (CFP) were selected as ETD amount, stabilizer type and ratio as well as critical process parameters (CPP) which were bead size, milling time and milling speed. The two-factorial-2³ and The Box-Benkhen Designs were generated to evaluate CFP and CPP, respectively. Particle size (PS), polydispersity index (PDI) and zeta potential (ZP) were analyzed as dependent variables. Characterization, physical stability and solubility studies were performed.

RESULTS

Optimum nanosuspensions stabilized by PVP K30 and Poloxamer 188 showed 188.5 ± 1.6 and 279.3 ± 6.1 nm of PS, 0.161 ± 0.049 and 0.345 ± 0.007 PDI, 14.8 ± 0.3 and 16.5 ± 0.4 mV of ZP values, respectively. The thermal properties of ETD did not change after milling and lyophilization process regarding to DSC analysis. Also, the crystalline state of ETD was preserved. The morphology of particle was smooth and spherical on SEM. The dry-nanosuspensions stayed physically stable for six months at room temperature. The solubility of nanosuspensions increased up to 13.0-fold in comparison with micronized ETD.

CONCLUSIONS

In conclusion, it is found that the poor solubility issue of ETD can be solved by nanosuspension. DoE approach provided benefits such as reducing number of experiments, saving time and improving final product quality by using wet media milling.

Emerging role of nanosuspensions in drug delivery systems

Rapid advancement in drug discovery process is leading to a number of potential new drug candidates having excellent drug efficacy but limited aqueous solubility. By virtue of the submicron particle size and distinct physicochemical properties, nanosuspension has the potential ability to tackle many formulation and drug delivery issues typically associated with poorly water and lipid soluble drugs. Conventional size reduction equipment such as media mill and high-pressure homogenizers and formulation approaches such as precipitation, emulsion-solvent evaporation, solvent diffusion and microemulsion techniques can be successfully implemented to prepare and scale-up nanosuspensions. Maintaining the stability in solution as well as in solid state, resuspendability without aggregation are the key factors to be considered for the successful production and scale-up of nanosuspensions. Due to the considerable enhancement of bioavailability, adaptability for surface modification and mucoadhesion for drug targeting have significantly expanded the scope of this novel formulation strategy. The application of nanosuspensions in different drug delivery systems such as oral, ocular, brain, topical, buccal, nasal and transdermal routes are currently undergoing extensive research. Oral drug delivery of nanosuspension with receptor mediated endocytosis has the promising ability to resolve most permeability limited absorption and hepatic first-pass metabolism related issues adversely affecting bioavailability. Advancement of enabling technologies such as nanosuspension can solve many formulation challenges currently faced among protein and peptide-based pharmaceuticals.

Development of daidzein nanosuspensions: Preparation, characterization, in vitro evaluation, and pharmacokinetic analysis

The purpose of this investigation was to improve the solubility and oral bioavailability of daidzein via preparing nanosuspensions (NS) with steric stabilizers, electrostatic stabilizers, or a combination of both. Based on particle size and zeta potential, daidzein NS stabilized by HP-β-CD, soy lecithin, HP-β-CD + soy lecithin, TPGS, TPGS + SBE-β-CD, SDS, or HPMC E5 + SDS were generated and characterized by scanning electron microscopy, powder X-ray diffraction, and Fourier transform-infrared spectroscopy. In addition, the stability, cytotoxicity, solubility, dissolution, and pharmacokinetics of NS were evaluated. The resulting daidzein NS were physically stable and biocompatible and presented as regular shapes with homogenous particle sizes of 360-600 nm and decreased crystallinity. Due to the increased solubility and dissolution rate, the oral bioavailability of daidzein NS in rats was 1.63-2.19 times greater than that of crude daidzein. In particular, among the investigated seven daidzein NS formulations, daidzein NS prepared with the costabilizers HPMC E5 + SDS is an optimal formulation for increased daidzein bioavailability. The present study proposes that the combined usage of steric and electrostatic stabilizers is a promising strategy for improving the bioavailability of water-insoluble flavonoid compounds by an NS approach.