Physicochemical, in vitro and in vivo evaluation of flurbiprofen microemulsion

Preparation, optimization and evaluation of Osthole transdermal therapeutic system

In the current study, the solubility and permeability of Osthole-loaded microemulsion were enhanced, which increased bioavailability. In addition, Carbomer 940 was added for prolonged drug delivery. The microemulsion was prepared after the screening of Kukui oil, Labrasol (surfactant), and transcutol-P (co-surfactant). Pseudoternary phase diagrams were employed to find the microemulsion region. Box Behnken Design (BBD) was employed for optimizing microemulsions. Variables were related and compared using mathematical equations and response surface plots (RSP). MEBG was then compared with control gel on the basis of stability studies, drug permeation, skin irritation studies, and anti-inflammatory studies. Microemulsion preparations depicted a pH of 5.27 - 5.80, a conductivity of 139 - 185 μS/cm, a poly-dispersity index of 0.116 - 0.388, a refractive index of 1.330 - 1.427, an average droplet size of 64 - 89 nm, homogeneity, spherical shape, viscosity 52 - 185 cP. Predicted values of Optimized microemulsions showed more reasonable agreement than experimental values. The microemulsion was stable and non-irritating on Rabbit skin. MEBG showed a significant difference from control gel for percent edema inhibition from the standard. The permeation enhancing capability of MEBG using a suitable viscosity fabricates it promising carrier for transdermal delivery of Osthole.

Sustained release gel (polymer-free) of itraconazole-loaded microemulsion for oral candidiasis treatment: time-kill kinetics and cellular uptake

Itraconazole (ICZ) was prepared in a self-microemulsifying (SM) gel. This gel was intended for use in the oral mucosa, where low volume and flow of saliva result in limited solubility and absorption of drugs that are poorly water-soluble. The drug-loaded gel formulation (ICZ-SM) was selected as a clear solution in the ternary phase diagram to improve the solubility of ICZ. Seven ratios (S1-S7) were prepared by mixing polyoxyl 35 castor oils (P35), a medium chain with a blend of mono-, di-, and triglycerides (MCT), and water. Phase separation of large-sized emulsions by countering with artificial saliva were observed in dilution tests for the formulation contained MCT, P35, and water at the ratios of 70:20:10 (S1), 10:80:10 (S3), and 20:60:20 (S4). Formulations in the ratios of 15:50:35 (S5) and 19:43:38 (S6) produced strong ICZ-SM gels, as shown by rheology tests, whereas the formulations at the ratios of 30:60:10 (S2) and 10:43:47 (S7) exhibited no elasticity. A model of zero-order kinetic (S5) and first-order kinetic (S6) were found to best fit the release kinetics of ICZ from the gels. Time-killing assays revealed that S5 and S6 required less time compared with S2 and the ICZ solution. Furthermore, S5 exhibited the highest increase in cell uptake compared with S2, S6, and the ICZ solution. These findings suggest that the ICZ-SM gel was a free polymer capable of delivering an ICZ for the treatment of oral candidiasis, and that ICZ-SM gels applied locally exhibit enhanced absorption into cells.

Tailoring Risperidone-Loaded Glycethosomal In Situ Gels Using Box-Behnken Design for Treatment of Schizophrenia-Induced Rats via Intranasal Route

Schizophrenic patients often face challenges with adherence to oral regimens. The study aimed to highlight the potentiality of intranasal ethanol/glycerin-containing lipid-nanovesicles (glycethosomes) incorporated into in situ gels for sustaining anti-psychotic risperidone (RS) release. The Box-Behnken Design (BBD) was followed for in vitro characterization. Glycethosomal-based in situ gels were examined by physical, ex vivo, and in vivo investigations. The ethanol impact on minimizing the vesicle size (VS) and enhancing the zeta potential (ZP) and entrapment efficiency (EE%) of nanovesicles was observed. Glycerin displayed positive action on increasing VS and ZP of nanovesicles, but reduced their EE%. After incorporation into various mucoadhesive agent-enriched poloxamer 407 (P407) in situ gels, the optimized gel containing 20% P407 and 1% hydroxypropyl methyl cellulose-K4M (HPMC-K4M) at a 4:1 gel/glycethosomes ratio showed low viscosity and high spreadability with acceptable pH, gel strength, and mucoadhesive strength ranges. The ethanol/glycerin mixture demonstrated a desirable ex vivo skin permeability of RS through the nasal mucosa. By pharmacokinetic analysis, the optimized gel showed eight-fold and three-fold greater increases in RS bioavailability than the control gel and marketed tablet, respectively. Following biochemical assessments of schizophrenia-induced rats, the optimized gel boosted the neuroprotective, anti-oxidant, and anti-inflammatory action of RS in comparison to other tested preparations. Collectively, the intranasal RS-loaded glycethosomal gel offered a potential substitute to oral therapy for schizophrenic patients.

Intranasal delivery of Clozapine using nanoemulsion-based in-situ gels: An approach for bioavailability enhancement

Limited solubility and hepatic first-pass metabolism are the main causes of low bioavailability of anti-schizophrenic drug, Clozapine (CZP). The objective of the study was to develop and validate nanoemulsion (NE) based in-situ gel of CZP for intranasal administration as an approach for bioavailability enhancement. Solubility of CZP was initially investigated in different oils, surfactants and co-surfactants, then pseudoternary phase diagrams were constructed to select the optimized ratio of oil, surfactant and co-surfactant. Clear and transparent NE formulations were characterized in terms of droplet size, viscosity, solubilization capacity, transmission electron microscopy, in-vitro drug release and compatibility studies. Selected NEs were incorporated into different in-situ gel bases using combination of two thermosensitive polymers; Pluronic® F-127 (PF127) and F-68 (PF68). NE-based gels (NG) were investigated for gelation temperature, viscosity, gel strength, spreadability and stability. Moreover, selected NGs were evaluated for ex-vivo permeation, mucoadhesive strength and nasal ciliotoxicity. Peppermint oil, tween 80 and transcutol P were chosen for NE preparation owing to their maximum CZP solubilization. Clear NE points extrapolated from tween 80:transcutol P (1:1) phase diagram and passed dispersibility and stability tests, demonstrated globule size of 67.99 to 354.96 nm and zeta potential of −12.4 to −3.11 mV with enhanced in-vitro CZP release (>90% in some formulations). After incorporation of the selected N3 and N9 formulations of oil:Smix of 1:7 and 2:7, respectively to a mixture of PF127 and PF68 (20:2% w/w), the resultant NG formulations exhibited optimum gelation temperature and viscosity with enhanced CZP permeation and retention through sheep nasal mucosa. Ciliotoxicity examinations of the optimum NGs displayed no inflammation or damage of the lining epithelium and the underlying cells of the nasal mucosa. In conclusion, NE-based gels may be a promising dosage form of CZP for schizophrenia treatment.

Fabrication, optimisation and evaluation of cisplatin-loaded nanostructured carriers for improved urothelium permeability for intravesical administration

AIM

To design microemulsions as carriers to improve cisplatin permeation capability for intravesical administration.

METHOD

The response surface methodology with factorial design was used to investigate and optimise the influence of the compositions e.g. capryol 90 and 5-pentanediol/transcutol mixture on the permeation accumulation amount and tissue deposition amount of cisplatin-loaded microemulsions. The in vitro permeation study and in vivo intravesical test were conducted to prove the effect of microemulsions.

RESULTS

The droplet size and the viscosity of all drug-loaded formulations ranged 235.8-309.3 nm and 550.8-861.7 cps, respectively. The permeation accumulation amounts significantly increased about 26-fold, by used microemulsion as carriers. In vivo study, the cisplatin deposition amount in bladder tissue significantly increased 4.1-fold (p < 0.05) and the penetration depth increased from 60 μm up 120 μm. The nanocarrier showed considerable thermodynamic stability.

CONCLUSION

The designed nanocarrier was considered to be a promising delivery system for cisplatin intravesical administration.

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.

Gel-Based Nanocarrier for Intravesical Chemotherapy Delivery: In Vitro and In Vivo Study

Intravesical administration of chemotherapeutic agents can enhance drug accumulation in tumors and reduce systemic side effects. Nanocarriers were developed for intravesical administration and exploit the permeation enhancement effect. In vitro permeation evaluation, the drug transdermal amount and accumulation amounts in the tissue of gemcitabine-loaded nanocarriers through biological membrane significantly increased about 14.8~33.0-fold and 1.5~14.1-fold respectively, when compared to a control group of 1% gemcitabine saline solution. In in vivo intravesical administration, the drug accumulation amount in bladder tissue of nanocarrier of 75.2 ± 5.4 μg was revealed as being comparably higher than that of the control group of 44.8 ± 6.4 μg. In confocal laser scanning microscopy imagery, the penetration depth of fluorescent dyes-rhodamine was increased from 80 μm up to 120 μm when a nanocarrier was used. This result implies that the nanocarrier is a promising drug delivery agent for intravesical administration.

Preparation and in vitro / in vivo evaluation of flurbiprofen nanosuspension-based gel for dermal application

Flurbiprofen (FB) is an analgesic and anti-inflammatory drug, but its low water solubility (BCS Class II) limits its dermal bioavailability. The aim of this study is to develop a FB nanosuspension (NS) based gel and to evaluate its analgesic and anti-inflammatory activities in rats. FB-NS was produced by the wet milling method with Plantacare 2000^Ⓡ, as stabilizer. The FB-NS was then incorporated in different carrier gels such as hydroxypropyl methyl cellulose (HPMC), polycarbophil, oleogel, and chitosan. To select the optimum gel type, visual examinations, pH and rheological property measurements, texture profile analysis, in vitro release and ex vivo permeation studies were performed. Following these tests, the analgesic and anti-inflammatory activities of the optimum NS based gel were evaluated using the tail flick and carrageenan-induced paw edema methods consecutively. The NS was successfully prepared with the wet milling method, and the PS, PDI and ZP values were found to be 237.7 ± 6.8 nm, 0.133±0.030, and -30.4 ± 0.7 mV; respectively. Among the NS-based gels, HPMC gel showed more suitable rheological and mechanical properties, also the percentage of permeated FB and the flux value observed for HPMC gel were higher for HPMC than for the other gels. Thus, HPMC gel was selected as a carrier gel for in vivo pharmacodynamics studies. The anti-inflammatory activity of FB-NS HPMC gel was higher than that of the physical mixture gel and that of the coarse suspension gel. Results of our analgesic activity studies showed that, in the 180th min of FB nanosuspension treatment, the latency time was significantly prolonged compared to that of the control group (p<0.05). As a conclusion, while nanosuspensions increased the in vivo pharmacodynamics effect of FB by means of nanosized particles and a large surface area, the HPMC gel as a carrier prolonged the contact time of NSs with skin and eased the dermal application.

Development of nanoemulsion gel drug delivery systems of cetirizine; factorial optimisation of composition, in vitro evaluation and clinical study

Aim: This work aimed to develop topical nanoemulsion gels of cetirizine, a second-generation antihistamine, to avoid its oral intake drawbacks and enhance skin permeation.Methods: Cetirizine nanoemulsions were formulated and characterised for their particle size, polydispersity index, zeta potential, drug release and drug permeation through rat skin. The optimised formulation, obtained using 2³ full factorial design, was incorporated in carbopol and chitosan gels and evaluated clinically for urticaria treatment.Results: The optimised formulation had particle size of 32.015 ± 1.87 nm, polydispersity index of 0.29 ± 0.04, zeta potential of -19.31 ± 0.43 mV, cetirizine percent released of 98.50 ± 1.23% and permeability coefficient of 7.65 cm.h^-1. Cetirizine nanoemulsion gels were more effective than their control gels in urticaria treatment with significant decrease in the degree of wheals and itching and higher recovery percent.Conclusion: Cetirizine nanoemulsion topical gels are expected to be a rational and effective tool for avoiding cetirizine oral side effects and targeting the affected skin.

Development of novel pH-sensitive nanoparticle-based transdermal patch for management of rheumatoid arthritis

Aim: To formulate and evaluate a pH-responsive nanoparticle (NP)-based patch for efficient transdermal delivery of flurbiprofen against rheumatoid arthritis. Materials & methods: Nanoprecipitation technique was used for preparation of NPs and central composite design was employed for optimization purposes. Optimized NPs were loaded into the transdermal patch by the solvent evaporation method. Results: Prepared NPs exhibited an average size of 69 nm, while NPs loaded onto the transdermal patch showed sustained release and high permeation through the skin. In in vivo studies, the prepared carrier system elucidated high therapeutic potential in both acute and chronic inflammatory models as evident from the results of behavioral, radiological, histopathological and antioxidant analyses. Conclusion: The flurbiprofen-loaded pH-sensitive NP-based transdermal patch has the potential to manage rheumatoid arthritis effectively.

Biomedical applications of microemulsion through dermal and transdermal route

Microemulsions are thermodynamically stable, transparent, colloidal drug carrier system extensively used by the scientists for effective drug delivery across the skin. It is a spontaneous isotropic mixture of lipophilic and hydrophilic substances stabilized by suitable surfactant and co-surfactant. The easy fabrication, long-term stability, enhanced solubilization, biocompatibility, skin-friendly appearance and affinity for both the hydrophilic and lipophilic drug substances make it superior for skin drug delivery over the other carrier systems. The topical administration of most of the active compounds is impaired by limited skin permeability due to the presence of skin barriers. In this sequence, the microemulsion represents a cost-effective and convenient drug carrier system which successfully delivers the drug to and across the skin. In the present review work, we compiled various attempts made in last 20 years, utilizing the microemulsion for dermal and transdermal delivery of various drugs. The review emphasizes the potency of microemulsion for topical and transdermal drug delivery and its effect on drug permeability.

Topical Nano and Microemulsions for Skin Delivery

Nanosystems such as microemulsions (ME) and nanoemulsions (NE) offer considerable opportunities for targeted drug delivery to and via the skin. ME and NE are stable colloidal systems composed of oil and water, stabilised by a mixture of surfactants and cosurfactants, that have received particular interest as topical skin delivery systems. There is considerable scope to manipulate the formulation components and characteristics to achieve optimal bioavailability and minimal skin irritancy. This includes the incorporation of established chemical penetration enhancers to fluidize the stratum corneum lipid bilayers, thus reducing the primary skin barrier and increasing permeation. This review discusses nanosystems with utility in skin delivery and focuses on the composition and characterization of ME and NE for topical and transdermal delivery. The mechanism of skin delivery across the stratum corneum and via hair follicles is reviewed with particular focus on the influence of formulation.

Encapsulation of Flurbiprofen by Chitosan Using a Spray-Drying Method with In Vitro Drug Releasing and Molecular Docking

Objectives

This study aimed to prepare chitosan-flurbiprofen micro-nano spheres as environmentally friendly for drug releasing by spray-drying method without any cross-linking agent. It was also aimed to reveal the favorable binding geometries of chitosan and flurbiprofen using molecular modeling.

Materials and Methods

In this study, flurbiprofen was encapsulated with chitosan using spray-drying technique. The used chitosan, flurbiprofen and obtained spheres were characterized via fourier transmission infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), X-ray diffractometer and scanning electron microscopy (SEM). Drug entrapment efficiency was carried out for determination of the drug amount in the micro-nano spheres. In vitro release studies of CS-FP spheres were also examined in the simulated biological fluid at pH 7.4. Encapsulation process of flurbiprofen was combined with the docking studies to investigate the possible binding sites of the chitosan.

Results

FT-IR results confirmed that H-bonding system was formed between chitosan and drug. CS-FP spheres with spherical shape were observed by SEM. TGA analysis results showed that thermal stabilities of flurbiprofen and chitosan were decreased after the encapsulation process. The spheres were used for in vitro releasing studies in simulated biological fluids. All these analysis results clearly showed that encapsulation was successfully carried out with 73.28% efficiency. Molecular modeling studies showed that CS-FP stable complexes was formed through a hydrogen bonding system between OH group of the drug molecule and chitosan hydroxyl (OH) group with a binding energy of -3.90 kcal/mol. Our computational results supported to spectroscopic results obtained by FTIR.

Conclusion

This study proved that micro-nano spheres can be prepared without using cross-linking agent by spray-drying method. The results of the drug releasing studies showed that release of encapsulated flurbiprofen was completed within 48h. The results of docking analysis can be suggested for the design of new drug carrier systems with chitosan.