Optimization and in vitro evaluation of ziprasidone nanosuspensions produced by a top-down approach

Dissolving microarray patches loaded with a rotigotine nanosuspension: A potential alternative to Neupro® patch

Parkinson's disease (PD), affecting about ten million people globally, presents a significant health challenge. Rotigotine (RTG), a dopamine agonist, is currently administered as a transdermal patch (Neupro®) for PD treatment, but the daily application can be burdensome and cause skin irritation. This study introduces a combinatorial approach of dissolving microarray patch (MAP) and nanosuspension (NS) for the transdermal delivery of RTG, offering an alternative to Neupro®. The RTG-NS was formulated using a miniaturized media milling method, resulting in a nano-formulation with a mean particle size of 274.09 ± 7.43 nm, a PDI of 0.17 ± 0.04 and a zeta potential of -15.24 ± 2.86 mV. The in vitro dissolution study revealed an enhanced dissolution rate of the RTG-NS in comparison to the coarse RTG powder, under sink condition. The RTG-NS MAPs, containing a drug layer and a 'drug-free' supporting baseplate, have a drug content of 3.06 ± 0.15 mg/0.5 cm2 and demonstrated greater amount of drug delivered per unit area (∼0.52 mg/0.5 cm2) than Neupro® (∼0.20 mg/1 cm2) in an ex vivo Franz cell study using full-thickness neonatal porcine skin. The in vivo pharmacokinetic studies demonstrated that RTG-NS MAPs, though smaller (2 cm2 for dissolving MAPs and 6 cm2 for Neupro®), delivered drug levels comparable to Neupro®, indicating higher efficiency per unit area. This could potentially avoid unnecessarily high plasma levels after the next dose at 24 h, highlighting the benefits of dissolving MAPs over conventional transdermal patches in PD treatment.

Factors affecting the preparation of nanocrystals: characterization, surface modifications and toxicity aspects

INTRODUCTION

The fabrication of well-defined nanocrystals in size and form is the focus of much investigation. In this work, we have critically reviewed several recent instances from the literature that shows how the production procedure affects the physicochemical properties of the nanocrystals.

AREAS COVERED

Scopus, MedLine, PubMed, Web of Science, and Google Scholar were searched for peer-review articles published in the past few years using different key words. Authors chose relevant publications from their files for this review. This review focuses on the range of techniques available for producing nanocrystals. We draw attention to several recent instances demonstrating the impact of various process and formulation variables that affect the nanocrystals' physicochemical properties. Moreover, various developments in the characterization techniques explored for nanocrystals concerning their size, morphology, etc. have been discussed. Last but not least, recent applications, the effect of surface modifications, and the toxicological traits of nanocrystals have also been reviewed.

EXPERT OPINION

The selection of an appropriate production method for the formation of nanocrystals, together with a deep understanding of the relationship between the drug's physicochemical properties, unique features of the various formulation alternatives, and anticipated in-vivo performance, would significantly reduce the risk of failure during human clinical trials that are inadequate.

Formulation Strategies of Nanosuspensions for Various Administration Routes

Nanosuspensions (NSs), which are nanosized colloidal particle systems, have recently become one of the most interesting substances in nanopharmaceuticals. NSs have high commercial potential because they provide the enhanced solubility and dissolution of low-water-soluble drugs by means of their small particle sizes and large surface areas. In addition, they can alter the pharmacokinetics of the drug and, thus, improve its efficacy and safety. These advantages can be used to enhance the bioavailability of poorly soluble drugs in oral, dermal, parenteral, pulmonary, ocular, or nasal routes for systemic or local effects. Although NSs often consist mainly of pure drugs in aqueous media, they can also contain stabilizers, organic solvents, surfactants, co-surfactants, cryoprotectants, osmogents, and other components. The selection of stabilizer types, such as surfactants or/and polymers, and their ratio are the most critical factors in NS formulations. NSs can be prepared both with top-down methods (wet milling, dry milling, high-pressure homogenization, and co-grinding) and with bottom-up methods (anti-solvent precipitation, liquid emulsion, and sono-precipitation) by research laboratories and pharmaceutical professionals. Nowadays, techniques combining these two technologies are also frequently encountered. NSs can be presented to patients in liquid dosage forms, or post-production processes (freeze drying, spray drying, or spray freezing) can also be applied to transform the liquid state into the solid state for the preparation of different dosage forms such as powders, pellets, tablets, capsules, films, or gels. Thus, in the development of NS formulations, the components/amounts, preparation methods, process parameters/levels, administration routes, and dosage forms must be defined. Moreover, those factors that are the most effective for the intended use should be determined and optimized. This review discusses the effect of the formulation and process parameters on the properties of NSs and highlights the recent advances, novel strategies, and practical considerations relevant to the application of NSs to various administration routes.

Nanosuspensions technology as a master key for nature products drug delivery and In vivo fate

The drug nanosuspensions is a universal formulation approach for improved drug delivery of hydrophobic drugs and one the most promising approaches for increasing the biopharmaceutical performance of poorly water-soluble drug substances, especially for nature products. This review aimed to summarize the nanosuspensions preparation approaches and the main technological difficulties encountered in nanosuspensions development, such as guidelines for stabilizers screening, in vivo fate of the intravenously administrated nanosuspensions, and how to realize the intravenously target delivery was reviewed. Furthermore, challenges of nanosuspensions for the nature products delivery also was discussed and commented. Therefore, it hoped to provide reference and assistance for the nanosuspensions production, stabilizers usage, and predictability of in vivo fate and controllability of targeting delivery of the nature products nanosuspensions.

Solubilization and Controlled Release Strategy of Poorly Water-Soluble Drugs

The processes of solubilization and controlled release of drugs that are poorly soluble in water are highly relevant in drug preformulation studies in pharmaceutical development [...]

Development of Nanocrystal Compressed Minitablets for Chronotherapeutic Drug Delivery

The present work aimed to develop a chronotherapeutic system of valsartan (VS) using nanocrystal formulation to improve dissolution. VS nanocrystals (VS-NC) were fabricated using modified anti-solvent precipitation by employing a Box−Behnken design to optimize various process variables. Based on the desirability approach, a formulation containing 2.5% poloxamer, a freezing temperature of −25 °C, and 24 h of freeze-drying time can fulfill the optimized formulation’s requirements to result in a particle size of 219.68 nm, 0.201 polydispersity index, and zeta potential of −38.26 mV. Optimized VS-NC formulation was compressed (VNM) and coated subsequently with ethyl cellulose and HPMC E 5. At the same time, fast dissolving tablets of VS were designed, and the best formulation was loaded with VNM into a capsule size 1 (average fill weight—400−500 mg, lock length—19.30 mm, external diameter: Cap—6.91 mm; Body—6.63 mm). The final tab in cap (tablet-in-capsule) system was studied for in vitro dissolution profile to confirm the chronotherapeutic release of VS. As required, a bi-pulse release of VS was identified with a lag time of 5 h. The accelerated stability studies confirmed no significant changes in the dissolution profiles of the tab in cap system (f2 similarity profile: >90). To conclude, the tab in cap system was successfully developed to induce a dual pulsatile release, which will ensure bedtime dosing with release after a lag-time to match with early morning circadian spikes.

A new nanosuspension prepared with wet milling method for oral delivery of highly variable drug Cyclosporine A: Development, optimization and in vivo evaluation

Cyclosporine A (CsA) is a cyclic polypeptide, that has been widely used for immunosuppression. This study aims to develop nanosuspension for oral administration of CsA using the wet milling (WM) method one of the top-down technologies. The WM method was optimized by studying the effects of critical process parameters for WM on the particle size (PS), particle size distribution (PDI), and zeta potential (ZP) of nanosuspensions using the Design of Experiment (DoE) approach. Nanosuspension was developed using hydroxypropyl methylcellulose (HPMC) and sodium dodecyl sulfate (SDS) and in vitro characterization studies were performed. In vitro dissolution and in vivo pharmacokinetic studies were conducted with biorelevant media (fasted and fed state simulated fluids) and fasted and fed states in rats, respectively. In vivo immunological studies were also performed. PS, PDI, and ZP values for nanosuspension were approximately 600 nm, 0.4, -25 mV, respectively. The solubility of CsA was increased by 4.5-folds by nanosuspensions. Dissolution studies showed that nanosuspension had higher dissolution than the commercial product in the FeSSIF medium. The pharmacokinetic study indicated that AUC_0-24 values of CsA nanosuspension were to be 2.09 and 5.51-fold higher than coarse powder in fasted and fed conditions, respectively. Immunological studies were carried out after oral administration of nanosuspension for 21 days, the ratio of CD4+/CD8+ was found to be more acceptable than the commercial product. These results demonstrated that nanosuspension is a promising approach for increasing the bioavailability and avoiding the food effect on absorption of CsA which one of the highly variable drugs.

Enhanced Dermal Delivery of Flurbiprofen Nanosuspension Based Gel: Development and Ex Vivo Permeation, Pharmacokinetic Evaluations

PURPOSE

The objective of this study was to optimize the Flurbiprofen (FB) nanosuspension (NS) based gel and to investigate the in vitro release, ex vivo permeation, the plasma concentration-time profile and pharmacokinetic parameters.

METHODS

FB-NSs were developed using the wet milling process with the Design of Experiment (DoE) approach. The optimum FB-NS was characterized on the basis of SEM, DSC, XRPD, solubility and permeation studies. The dermal gel was prepared by incorporating FB-NS into HPMC gel. Then the in-vitro release, ex vivo permeation studies were performed, and pharmacokinetic studies were evaluated on rats.

RESULTS

The particle size, polydispersity index and zeta potential values of optimum NS were determined as 237.7 ± 6.8 nm, 0.133 ± 0.030 and - 30.4 ± 0.7 mV, respectively. By means of the surfactant content and nanosized particles of the nanosuspension, the solubility of FB was increased about 7-fold. The percentage permeated amount of FB from FB-NS gel (8.40%) was also found to be higher than the physical mixture (5.25%) and coarse suspension (reference) (2.08%) gels. The pharmacokinetic studies showed that the C_max of FB-NS gel was 2.5 times higher than the reference gel, while AUC_0-24 was 2.96 times higher.

CONCLUSION

FB-NSs were successfully prepared with a wet milling method and optimized with the DoE approach. The optimized FB nanosuspension gel provided better permeation and pharmacokinetic performance compared to FB coarse suspension gel.

Schizophrenia; A Review on Promising Drug Delivery Systems

Background:

Schizophrenia belongs to mental illnesses affecting 1% of the worldwide population. Its therapy is still unmet; thus, researchers aimed to develop new pharmacological molecules which can improve its management.

Methods:

Moreover, the current typical and atypical antipsychotics should be formulated in more efficacious systems that can deliver the drug in the brain with as few side effects as possible. Further, the development of long-acting efficient drug delivery systems could be significant in minimizing frequent dosing which is nonpreferred to schizophrenics.

Results:

Herein, authors focused on current developments of antipsychotic medications used in schizophrenia management. Various studies, which include the use of first and second-generation antipsychotics, were analyzed according to their efficacy. In fact, in this review, oral, injectable, transdermal and intranasal formulations entrapped antipsychotics are presented to be valuable guidance for scientists to formulate more effective drug delivery systems for schizophrenic patients.

Conclusions:

This review aimed to assist researchers working on schizophrenia management by summarizing current medications and newly synthesized drug delivery systems recently found in the literature.

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.

Development of Nanocrystal Ziprasidone Orally Disintegrating Tablets: Optimization by Using Design of Experiment and In Vitro Evaluation

The objective of the current study was to develop ziprasidone hydrochloride monohydrate (ZHM) nanocrystal-based orally dispersible tablet (ODT) formulations. Design of experiment approach was used to develop ODTs. The tablets were compressed using direct compression method and characterized with quality control tests. In vitro dissolution studies and Caco-2 cell permeability tests were executed. The hardness and friability values of nanocrystal-based ODTs were found 31.2 N and 1.05%, respectively. The disintegration time was below 10 s. Dissolution profile in pH 7.4 phosphate buffer showed that nanocrystal-based ODTs and commercial product were dissolved in 120 min 58.98% and 16%, respectively. In pH 7.4 phosphate buffer with SLS, sample groups dissolved above 85% at the end of the study. Permeability value and cumulative ZHM amount on the cells were improved with nanocrystals. In conclusion, the novel formulation of ZHM nanocrystal-based ODTs was successfully developed for alternative dosage form.