Design and evaluation of amphotericin b and luliconazole nanoemulsions for targeted antifungal delivery

Optimization of processing parameters for the development of Ficus religiosa L. extract loaded solid lipid nanoparticles using central composite design and evaluation of antidiabetic efficacy

Background and Introduction: Saxagliptin is a hypoglycemic drug that acts as a dipeptidyl peptidase-4 (DPP-4) inhibitor and is preferably used in the treatment of Type 2 Diabetes Mellitus (T2DM). It is safe and tolerable; however, the major disadvantage associated with it is its low bioavailability. Aim: The present research aimed to enhance the bioavailability of the drug by enteric coating with a polymer that controls the rate of drug delivery, and it was prepared as Solid Lipid Nanoparticles (SLNs). Methodology: In the current study, various SLN formulations were developed using a central composite design (CCD) module using Design Expert-11 software. A modified solvent injection technique was used to prepare Saxagliptin nanoparticles coated with Eudragit RS100. The CCD was used to determine the independent variables and their effect on dependent variables at varied levels. Evaluation studies such as particle size analysis, Zeta potential, polydispersity index (PDI), drug loading, entrapment efficiency, in-vitro drug release studies, and in vivo pharmacokinetic studies were performed for the optimized SLN formulation. The reversed-phase HPLC method was developed and validated for the estimation of the pharmacokinetic parameters of the pure drug and prepared SLNs. Results: The effect of independent variables (A1: amount of lipid, A2: amount of polymer, A3: surfactant concentration, and A4: homogenization speed) on dependent variables (R1: particle size, and R2: entrapment efficiency) was established in great detail. Observed responses of the prepared and optimized Saxagliptin SLN were close to the predicted values by the CCD. The prepared SLNs depicted particle sizes in the range of 212–442 nm. The particle size analysis results showed that an increase in the lipid concentration led to an increase in particle size. The developed bioanalytical method was noted to be very specific and robust. The method accuracy varied from 99.16% to 101.95% for intraday, and 96.08% to 103.12% for inter day operation at low (5 mcg/mL), moderate (10 mcg/mL), and higher (15 mcg/mL) drug concentrations. The observed Zeta potential values for the prepared SLNs were in the range of −41.09 ± 0.11 to 30.86 ± 0.63 mV suggesting quite good stability of the SLNs without any aggregation. Moreover, the polydispersity indices were in the range of 0.26 ± 0.051 to 0.45 ± 0.017, indicative of uniformity of sizes among the prepared SLNs. In vivo study outcomes proved that Saxagliptin oral bioavailability significantly enhanced in male Albino Wistar Rats via SLN formulation and Eudragit RS100 coating approach. Conclusions: The developed and optimized Saxagliptin SLNs revealed enhanced Saxagliptin bioavailability in comparison to the native drug. Thus, this formulation strategy can be of great importance and can be implied as a promising approach to enhance the Saxagliptin bioavailability for facilitated T2DM therapy.

The objective of this work was to design and characterize liquid and solid self-emulsifying drug delivery systems (SEDDS) for poorly soluble Dolutegravir Sodium. To optimize the composition of liquid Dolutegravir Sodium-SEDDS, solubility tests, pseudoternary phase diagrams, emulsification studies and other in vitro examinations (thermodynamic stability, droplet size and zeta potential analysis) were performed. The central composite design was employed to optimize the formulation variables, Capmul MCM (oil), Tween 80 (surfactant) and Propylene glycol (co-surfactant). Liquid self-emulsifying drug delivery system was appraised for determination of self emulsifying time, globule size and drug release. TEM study confirmed the uniform oil globules of the optimized liquid formulation. The optimized liquid formulation was formulated into free-flowing powder (S-SEDDS) by adsorption on the materials like Aerosil 200, Neusilin US2 and compressed into tablets. The solid state characterization of S-SEDDS powder was performed by using DSC, PXRD and SEM to investigate the physical nature of the drug. Further, the accelerated stability studies for 6 months revealed that S-SEDDS of Dolutegravir Sodium was found to be stable without any significant change in physico-chemical properties. S-SEDDS of Dolutegravir Sodium with improved dissolution profile was successfully prepared by using Neusilin US2 as an adsorbent carrier as compared to marketed sample.

Introduction: A self-nanoemulsifying drug delivery system (SNEDDS) has been explored to improve the solubility and dissolution rate of poorly water-soluble drug clopidogrel. Materials and Methods: Different formulations were prepared using an oil, surfactant, and cosurfactant in varying ratios. A pseudo-ternary phase diagram was constructed to identify the self-nanoemulsification region. Further, the resultant formulations were investigated for clarity, phase separation, drug content, % transmittance, globule size, freeze-thaw method, in vitro dissolution studies, particle size analysis, and zeta potential. Results: On the basis of particle size, zeta potential and dissolution profile and other studies, F6 was found to be the best formulation of clopidogrel SNEDDS. The particle size of the emulsion is a crucial factor in self-emulsification performance because it determines the rate and extent of drug release as well as absorption. The particle size of the optimized SNEDDS formulation was found to be 5.2 nm and zeta potential was found to be ‒29 mV which comply with the requirement of the zeta potential for stability. The % release from optimized SNEDDS formulation F6 was highest (98.93%) and faster than other SNEDDS formulations and pure drug substance (32%) indicating influence of droplet size on the rate of drug dissolution. The faster dissolution from SNEDDS may be attributed to the fact that in this formulation, the drug is a solubilized form and on exposure to dissolution medium results in small droplet that can dissolve rapidly. Fourier transform infrared data revealed no physicochemical interaction between drug and excipients. Conclusion: Thus, clopidogrel with SNEDDS formulation may be used for the improvement of solubility and dissolution rate for the effective management of heart disease.

Clotrimazole (CTZ) is a broad spectrum antimycotic agent known to be very effective locally for the treatment of fungal skin infections. The aim of this study was to study the effect of chitosan-coated microemulsion (CME) for topical delivery of CTZ and also evaluate its in vitro antifungal efficacy, ex vivo permeation and retention ability on the skin surface. The pseudo-ternary phase diagrams were developed using clove oil as oil phase, Tween 80 and propylene glycol as surfactant and co-surfactant, respectively, and distilled water as aqueous phase. CME was prepared by the drop wise addition of chitosan solution to the optimized microemulsion. Physicochemical parameters (globule size, zeta potential, drug content, viscosity and pH) and in vitro release of CME were studied. The in vitro antifungal efficacy of CME and ME was studied by cup-plate method against Candida albicans. Ex vivo drug permeation study was also carried out in a modified diffusion cell, using rat skin. The developed CME displayed an average globule size less than 50 nm and a positive surface charge, acceptable physico-chemical behavior, and exhibited sustained drug release in in vitro study. In in vitro anti-fungal study, CME showed greater values of zone of inhibition as compared to ME due to its prolonged action as well as fungistatic nature of chitosan. In ex vivo study, CME showed better retention and sustained permeation property than ME due to the mucoadhesive property of chitosan. These results suggest that positively charged CMEs could be used as novel topical formulation for its ability to retain on the skin and its ability to sustain the release of the drug.

In the present study, water-in-oil (w/o) microemulsions were prepared, evaluated, and optimized using pseudoternary phase diagram and central composite design (CCD). Ternary phase diagrams were designed to determine the microemulsion region whereas face-centered CCD helped in the determination of the effect of variables like oil type and surfactant ratio on globule size and viscosity of w/o microemulsion. The design exhibited that the factors have statistically significant effects (p < 0.0001) on the selected responses. The actual responses showed excellent agreement with the predicted values as suggested by the CCD with lower residual standard error. Similarly, the optimized values were found within the range as predicted by the model. Furthermore, other characteristics of microemulsions like pH, conductivity, refractive index, and transmittance were also analyzed. Overall, the primary objective of the research was to fabricate water-in-oil microemulsions which could facilitate effective delivery of hydrophilic molecules and drugs.

Objective: The present research was aimed to develop ketoconazole (KT) loaded microemulsion-based gel formulation for effective topical delivery through enhanced drug solubility, improved skin permeation and reduced side effects overcoming drawbacks of conventional dosage forms. Methods: For the selection of oil, surfactant and co-surfactant mixture (Smix) ratio, the phase titration method was used and pseudo-ternary phase diagrams were prepared. D-optimal mixture design was employed to optimize the microemulsion system taking oil, Smix and water as independent variables and particle size, polydispersity index, zeta potential, % transmittance and cumulative % drug release as response variables. Finally, topical gel formulation of KT-loaded microemulsion was developed and evaluated for physico-chemical properties, rheological properties, in vitro drug release kinetics and ex-vivo drug permeation. Results: The optimized microemulsion was found to be a transparent formulation with 19.7 nm particle size, 0.268 polydispersity index,-0.2 mV zeta potential, 97.83% transmittance and 85.85% cumulative drug release at 24 h. The developed gel of optimized microemulsion possessed pH 6.20, viscosity 2178 cps, spreadability 18.634 g.cm2/sec, adhesiveness 45.989 N/mm2, and cohesiveness-85.583. The in vitro drug release was found to be 69.08 % (at 24 h), showing sustained release and Higuchi kinetic profile. The developed gel exhibited 1.84-fold higher drug permeation flux as compared to the marketed product. Conclusion: The developed gel formulation possessed all desired quality attributes and physico-chemical properties. The in vitro and ex-vivo study data proved it’s suitability as a better alternative to conventional products in the effective treatment of fungal skin infections.

Objective: The objective of this study was to develop, characterize, and conduct pharmacokinetic and pharmacodynamic studies on ursolic acid solid self microemulsifying drug delivery system (UA-S-SMEDDS) for the treatment of diabetic complications. Methods: Liquid self microemulsifying drug delivery system (L-SMEDDS) were made with Capryol 90 as an oil, Cremophor EL as a surfactant, and polyethylene glycol (PEG) 400 as a co-surfactant. The surfactant and co-surfactant (Smix) ratios were calculated using a pseudo ternary phase diagram. At different pH levels and with water, the globule size, polydispersity index (PDI), zeta potential (ZP), and dilution were all assessed. S-SMEDDS has developed adsorption to a solid carrier by utilizing L-SMEEDS formulation. The powder properties, liquid retention potential, globule size, PDI, ZP, assay, and pharmacokinetic studies were all evaluated. The pharmacodynamic investigations of the S-SMEDDS formulation in streptozotocin (STZ) induced Wistar rats were evaluated using malondialdehyde (MDA) and glutathione (GSH) determination in tissues and section studies. Results: S-SMEDDS formulation was successfully developed with a droplet size of 163.4±1.475 nm, PDI of 0.251±0.042, a ZP of-21.3±1.02, an assay of 96.21±0.75%. The release studies showed 26.28% (0.1N HCl) and 83.57% (6.8 phosphate buffer) were released in 15 min. When comparing the pharmacokinetics of a UA-loaded S-SMEDDS to the coarse suspension, the S-SMEDDS (F2A) showed a 4.12 fold improvement in UA oral bioavailability. The pharmacodynamic results showed that S-SMEDDS was a higher recovery rate. Conclusion: The developed solid SMEDDS (F2A) formulation proved effective in treating diabetic complications in STZ induced Wistar rats by inhibiting the aldose reductase enzyme.

The objective of the present study was to enhance the solubility, dissolution and hence anti-inflammatory activity of poorly soluble drug indomethacin (IMN) by formulating into self emulsifying systems. Self emulsifying formulations were prepared using capmul MCM as oil, tween 80 as surfactant, transcutol P as cosurfactant. Fourier transform infrared spectroscopy and differential scanning calorimetry studies were conducted to know the interaction between drug and excipients. Pseudo ternary phase diagrams were constructed using surfactant and cosurfactant in 1:1 to 1:4 and 2:1 to 4:1 to know the efficient self emulsification region. The formulations were evaluated for their particle size, zeta potential, refractive index, viscosity and cloud point. In vitro dissolution studies were conducted in one part of pH 7.2 phosphate buffer and four parts of water. The pharmacokinetic parameters were analysed by Win Nonlin software. The self emulsification was higher with the ratios 2:1, 3:1 and 1:2 of surfactant and co surfactant and the IMN formulations were prepared. The formulations were stable at different pH and dilutions. The globule size was in the range of 184.1 nm to 340.5 nm, as the ratio of oil, surfactant and cosurfactant mixture has varied effects on the size of globule. The negative charge on the globules of all formulations attributes their stability. The optimized formulation showed better release as compared to marketed product. The AUC of the optimised Self-Emulsifying Drug Delivery System was significantly higher than the marketed product. Thus, from the present research, self emulsifying systems of IMN provide a useful alternative to enhance dissolution and hence anti inflammatory activity.

<p style="text-align: justify;"><strong>Objective:</strong> The purpose of this study was to developed microemulsion based gel formulation for topical delivery of dapsone with an objective to increase the solubility and skin permeability of the drug for treatment of acne. <strong>Methodology:</strong> The solubility of dapsone in oils, surfactants and cosurfactants was evaluated by saturation solubility to screen the components of the microemulsion. The pseudoternary phase diagrams were constructed using capryol 90 and N-methyl-2 pyrrolidone as the oil phase, Kolliphor EL as surfactant and PEG 400 as the co-surfactant. The system were assessed for drug-loading efficiency and characterized for pH, conductance, viscosity, particle size, drug content, globule size, zeta potential and drug release. Optimized formulation systems were formulated into gel form by using poloxamer- 407 and evaluated for viscosity, spreadability, drug content, stability, in-vitro skin permeation, steady state flux, permeability coefficient, enhancement ration and skin irritation study. <strong>Result and Discussion:</strong> Globule size of optimized microemulsion (F2) was found to be 27.53 nm, zeta potential was found to be-14.6 mV, permeability of drug from microemulsion within 8h was observed 82%, In- vitro diffusion study showed increase in flux of microemulsion based gel (392.43 &mu;g cm-2 h-1) to that of simple dapsone gel (274.4 &plusmn; 0.78 &mu;g cm-2h-1). Draize test revealed absence of irritation and inflammation on rat skin. <strong>Conclusion:</strong> Microemulsion based gel of dapsone formulation provided better application property and stability in comparison to simple gel. <p style="text-align: justify;"><strong>Key words:</strong> Acne vulgaris, Dapsone, Flux, <em>In-vitro</em> skin permeation, Topical delivery.

Darifenacin hydrobromide, a BCS Class II drug, is poorly bioavailable due to extensive first-pass metabolism. The present study is an attempt to investigate an alternative route of drug delivery by developing a nanometric microemulsion-based transdermal gel for the management of an overactive bladder. Oil, surfactant, and cosurfactant were selected based on the solubility of the drug, and surfactant: cosurfactant in surfactant mixture (Smix) was selected at a 1:1 ratio as inferred from the pseudo ternary phase diagram. The D-optimal mixture design was used to optimize the o/w microemulsion wherein the globule size and zeta potential were selected as dependable variables. The prepared microemulsions were also characterized for various physico-chemical properties like transmittance, conductivity, and TEM. The optimized microemulsion was gelled using Carbopol 934 P and assessed for drug release in vitro and ex vivo, viscosity, spreadability, pH, etc. Drug excipient compatibility studies showed that the drug was compatible with formulation components. The optimized microemulsion showed a globule size of less than 50 nm and a high zeta potential of -20.56 mV. The ME gel could sustain the drug release for 8 hours as reflected in in vitro and ex vivo skin permeation and retention studies. The accelerated stability study showed no significant change in applied storage conditions. An effective, stable, non-invasive microemulsion gel containing darifenacin hydrobromide was developed. The achieved merits could translate into increased bioavailability and dose reduction. Further confirmatory in vivo studies on this novel formulation, which is a cost-effective & industrially scalable option, can improve the pharmacoeconomics of overactive bladder management.

BackgroundThe main objective of the present study was to formulate, optimize and characterize solid lipid nanoparticles (SLNs) loaded with Atorvastatin Calcium (ATS) and Vinpocetine (VIN) as a potential drug delivery system to improve its solubility and assess its anti-tumor activity on cell lines. The SLNs were formulated by emulsification with high speed homogenization followed by probe sonication. Central composite design was selected for optimization. Drug: lipid ratio, surfactant: co-surfactant ratio and homogenization speed were considered critical process parameters (CPP) to study the effects on critical quality attributes (CQA) of SLNs i.e. particle size, percent entrapment efficiency (% EE) and percent drug loading (% DL).ResultsThe optimized (F3) SLNs formulations were characterized by transmission electron microscopy (TEM), X- ray diffraction (X-RD), in vitro drug release by dialysis bag method and stability studies. In vitro cell line studies were performed on HepG2, MCF 7 and melanoma B16 F10 cell line. The optimized F3 formulation showed a particle size of 323 ± 6 nm, poly dispersity index (PDI) 0.333 ± 0.02, Zeta potential (ZP) − 30.4 ± 0.66 emv with % EE 64.69 ± 1.1; 65.98 ± 0.91 of ATS and VIN respectively. In vitro release (F3) of ATS and VIN in PBS pH 7.4 was found to be 89.45% and 91.86%, respectively, up to 24 h.ConclusionsIn vitro cell line study demonstrated that SLNs enhanced the anti-cancer activity of ATS, VIN on all the stated cell lines when compared with free drugs. Combination index (CI) for HEPG2 was 0.8, which signified synergistic effect. The results exhibited that SLNs is effective, stable and had enhanced activity against HepG2, MCF 7 and melanoma B16 F10 cell lines.

The aim of the current study is to establish a comprehensive experimental design for the screening and optimization of Atorvastatin-loaded nanostructured lipid carriers (AT-NLCs). Initially, combined D-optimal screening design was applied to find the most significant factors affecting AT-NLCs properties. The studied variables included mixtures of solid and liquid lipids, the solid/liquid lipid ratio, surfactant type and concentration, homogenization speed as well as sonication time. Then, the variables homogenization speed (A), the ratio of solid lipid/liquid lipid (B), and concentration of the surfactant (C) were optimized using a central composite design. Particle size, polydispersity index, zeta potential, and entrapment efficiency were chosen as dependent responses. The optimized AT-NLCs demonstrated a nanometric size (83.80 ± 1.13 nm), Polydispersity Index (0.38 ± 0.02), surface charge (−29.65 ± 0.65 mV), and high drug incorporation (93.1 ± 0.04%). Fourier Transform Infrared Spectroscopy (FTIR) analysis showed no chemical interaction between Atorvastatin and the lipid mixture. Differential Scanning Calorimetry (DSC) analysis of the AT-NLCs suggested the transformation of Atorvastatin crystal into an amorphous state. Administration of the optimized AT-NLCs led to a significant reduction (p < 0.001) in serum levels of rats’ total cholesterol, triglycerides, and low-density lipoproteins. This change was histologically validated by reducing the relevant steatosis of the liver.

Development of propylated starch-based nanoparticles for Amphotericin B delivery.

Objective: The objective of this work was to perform pre-formulation studies, prepare, and optimize microemulsion containing valerian root extract, and evaluate the prepared microemulsion liquid containing valerian root extract. Methods: Valerian roots were subjected to extraction by maceration and percolation methods. The microemulsion formulation was prepared using different concentrations of peanut oil as an oil phase, Tween 20 as a surfactant, and span 80 as a cosurfactant. Pseudoternary phase diagrams were constructed to identify the microemulsion region, and a suitable composition was identified to formulate the microemulsion. The microemulsion was evaluated for viscosity, pH, staining test, globule size, zeta potential, and transmission electron microscopy. Results: The extractive value of valerian root in 70% ethanol was the maximum (27.56±1.95% w/w). Based on the thin-layer chromatography experiment, the reported Rf value for valerenic acid is 0.48. Peanut oil showed the highest solubilization capacity for the drug, i.e., 7.00±0.02 mg/mL. The optimized F4 formulation showed viscosity 110±7.9cP, pH 6.22±2.00, globule size 96.78±10.9, and zeta potential +67.5±1.9. The staining test for the optimized formulation (F4) indicated that the emulsion is an zo/w type of microemulsion. Conclusion: This novel delivery of the drug in the oral cavity may ensure the quick and full release of the drug without interfering with the food, pH, enzymatic degradation, and gastric motility. This formulation containing herbal drug may offer an alternative natural solution for the treatment of insomnia.