Comparative Study of the Antimicrobial Activity of Combined Topical Medicinal Formulations of Betamethasone,Gentamicin, and Clotrimazole In Vitro

Pharmaceutical Chemistry Journal - We present here the results of an experimental study of the antimicrobial activity of combined topical medicinal formulations of betamethasone, gentamicin, and...     

Development of Liposomal Systems of Finasteride for Topical Applications: Design,Characterization, and In Vitro Evaluation

Finasteride (FNS) is a “drug of choice” for benign prostate hypertrophy and prostate cancer. The drug has also been reported to be useful orally in the treatment of some difficult-to-treat androgen-dependent skin disorders, such as seborrhea, acne, hirsutism, and androgenetic alopecia. However, the ideal route for its administration (i.e., topical) remains unexplored. This has logically suggested the search for strategic formulation approaches to make the drug effective on topical applications, hitherto unexplored. The present study targets the encasement of drug molecules in the interiors of vesicular compartments (liposomes) made up of hydrogenated phospholipids, as an attempt toward the development of a trans-epidermal therapeutic system of FNS. Multilamellar drug-loaded liposomes were prepared by thin-film hydration with sonication method and optimized with respect to drug payload, entrapment efficiency, and size by formulating different vesicular compositions under different process conditions. The vesicular systems consisting of saturated phospholipid (100 mg), cholesterol (50 mg), and FNS (5 mg) showed highest drug payload (2.9 mg/100 mg of total lipids), and drug entrapment efficiency (88.6%). Mean (± SD) vesicle size of the prepared liposomes was found to be 3.66 ± 1.6 μm. Significantly higher skin permeation of FNS through excised abdominal mice skin of FNS was achieved from the liposomal formulations vis-à-vis corresponding solution and conventional gels. Liposomal FNS formulations also showed more than fivefold higher deposition of drug in skin than the corresponding plain drug solution and conventional gel. Stability studies indicated that the liposomal formulations were quite stable in the refrigerated conditions for 2 months with negligible drug leakage or vesicle size alteration during the storage period. Results of the current studies with FNS-loaded vesicular systems project the high plausibility of a topical liposomal formulation for effective localized delivery of Finasteride.     

Synthesis,Characterization and In Vitro Antimicrobial Evaluation of Novel Pyrazolothiazol-4(5H)-one Derivatives

Antimicrobial screening of several novel pyrazolothiazol-4(5H)-one derivatives (3a-3j) has been performed. Reaction of aromatic aldehydes with aromatic ketones yielded starting chalcones (1a-1j) which have been subsequently reacted with thiosemicarbazide for obtaining N-thiocarbamoylpyrazole derivatives (2a-2j). These were further cyclized to pyrazolothiazol-4(5H)-one derivatives (3a-3j) in the presence of ethylbromoacetate. The structures of newly synthesized compounds were confirmed by FTIR and ¹H NMR and/or MS. The in vitro antimicrobial activity of these compounds was evaluated against Gram positive bacteria, Gram negative bacteria and fungi. Their minimum inhibitory concentration was determined by tube dilution method. The results showed that most of the compounds have promising antimicrobial activity as compared to standard drugs. Among the test compounds, 2-[5(4-chlorophenyl)-3-phenyl-4,5-dihydropyrazol-1-yl]-thiazol-4(5H)-one (3e) was found to show the most potent antimicrobial activity.     

Topical Formulations of Serratiopeptidase: Development and Pharmacodynamic Evaluation

Serratiopeptidase, an enzyme derived from Serratia marcescences strain E-15 (ATCC 21074), present in the gut wall of the silk worm possesses anti-inflammatory properties, and can prove to be a suitable alternative to commonly used non steroidal antiinflammatory agents. Being sensitive to gastric degradation, serratiopeptidase is conventionally given orally in the form of enteric coated tablet formulations. Topical formulations of serratiopeptidase would be useful to treat local inflammations and may prove to be more effective compared to non steroidal antiinflammatory agents. The present study investigates the feasibility of developing topical preparations of serratiopeptidase in the form of ointments and gels. Excipient compatibility of serratiopeptidase with various excipients and polymers, formulation development, characterization and stability studies have been carried out. Stable formulation was evaluated for anti-inflammatory activity by oxazolone induced ear edema method in mice and allergenic potential by passive cutaneous anaphylaxis.     

Development of a Thermosensitive In-Situ Gel Formulations of Vancomycin Hydrochloride: Design,Preparation, In Vitro and In Vivo Evaluation

The purpose of this study was to develop a thermosensitive in situ gel delivery system based on Poloxamer 407 and Poloxamer 188 for ocular administration of vancomycin to treat systemic diseases. The vancomycin thermosensitive in situ gel was characterized using differential scanning calorimetry, rheological and drug release analyses. Additionally, pharmacokinetic studies and irritation tests of the gel were conducted after ocular administration in rabbits. The gel maintained a flowing liquid state under non-physiological conditions (25°C) to facilitate administration, and it transformed into a semi-solid state under physiological conditions (dilution with tears, 34°C), which prolonged its retention time in the eye. The gel erosion and drug release tests showed an excellent linear relationship between the cumulative drug release rate and the cumulative gel erosion rate, indicating a zero-order kinetic process. The pharmacokinetic analyses showed that the peak concentration, area under the curve, and bioavailability of the vancomycin thermosensitive in situ gel were 1.44, 1.98 and 1.93 times greater, respectively, that the values of vancomycin eye drops. Therefore, thermosensitive in situ gel may serve as a drug delivery system that can overcome the limitations of existing formulations of small-molecule peptides.     

In Vitro Evaluation of Nebulization Properties,Antimicrobial Activity,and Regional Airway Surface Liquid Concentration of Liposomal Polymyxin B Sulfate

Purpose. To manipulate the activity of polymyxin B sulfate (PXB sulfate) by encapsulation in liposomes derived from appropriately selected surfactants that exhibit optimum entrapment and aerosol delivery of encapsulated PXB sulfate. Methods. A combination of phospholipid (DMPG) and nonionic surfactants (Span 20 + Tween 80) was selected to encapsulate PXB sulfate. The nebulization properties were evaluated by nebulizing the liposomal dispersions with Pari LC Star nebulizers. The in vitro antibacterial activities of the original and nebulized liposomal formulations were evaluated against Pseudomonas aeruginosa (ATCC 27853) strains by broth microdilution, and their minimum inhibitory concentrations (MICs) were compared with those of free PXB sulfate and colistin methanesulfonate. Measurements of the aerosol properties during nebulization were used as input for a mathematical model of airway surface liquid in the lung of an average adult, to estimate the airway surface liquid concentration of the deposited liposomal PXB sulfate. Results. The selected combination of surfactants showed maximum nebulization efficiency without compromising liposomal integrity during nebulization. PXB sulfate was added at a concentration of 10 mg/ml, and a molar ratio of PXB sulfate to dimyristoyl phosphatidylglycerol (DMPG) (sodium salt) of 1:5 was required to achieve 100% entrapment of PXB sulfate and no leakage on nebulization. Another formulation comprising half the concentrations of the optimized nonionic surfactants and DMPG was prepared to achieve a balance between the toxicity and efficacy after nebulization of encapsulated PXB sulfate. The in vitro antibacterial activities against Pseudomonas aeruginosa indicated that the activity of PXB sulfate could be manipulated by appropriate concentrations of the selected surfactants to achieve activity equivalent to that of colistin methanesulfonate, which is known to be less toxic than unencapsulated PXB sulfate. The estimated airway surface liquid concentrations of the deposited liposomal PXB sulfate reveal that the MIC of the nebulized liposomal PXB sulfate can be achieved over most of the tracheobronchial region, using a jet nebulizer with a volume fill of 2.5 ml or more. Conclusions. It was established from this study that the encapsulation of PXB sulfate in liposomes reduces its activity against P. aeruginosa strains. Concentrations of PXB sulfate deposited in the tracheobroncial region, predicted using a mathematical model, were above the measured MICs except in the case of very high mucus production rate and low mucus velocities.     

Evaluation of Monooleine Aqueous Dispersions as Tools for Topical Administration of Curcumin: Characterization,In Vitro and Ex-Vivo Studies

Curcumin (CUR) is a well-known natural compound showing antioxidant, anti-inflammatory, and antitumor abilities but characterized by poor bioavailability and chemical instability, which drastically reduce its application in the treatment of chronic diseases such as osteoarthritis. The aim of the present study is the design and evaluation of monooleine aqueous dispersion (MAD) as novel carriers for the topical administration of CUR. CUR-loaded MAD was formulated using two different emulsifier systems, namely poloxamer 407 (MAD-A) and sodium cholate-sodium caseinate (MAD-B). These vehicles were characterized, and their influence on in vitro percutaneous absorption of CUR was also evaluated. Furthermore, an oxygen radical absorbance capacity assay was used to determine their antioxidant activity, and a Western blot analysis was performed to evaluate the inhibitory effect of the formulations on inducible nitric oxide synthase and cyclooxygenase 2 expressions. From the obtained results, CUR encapsulation efficiency was higher than 98% for MAD-A and 82% for MAD-B. Shelf-life studies showed that MAD-A maintains CUR stability better than MAD-B, and both vehicles demonstrated, in vitro, control of drug diffusion through the skin. Finally, MAD-A and MAD-B were able to extend the antioxidant/anti-inflammatory effects of CUR, also confirming the protective effect toward CUR chemical stability. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2349–2361, 2013     

Formulation,Characterization, and In Vitro Evaluation of Silymarin-Loaded Lipid Microspheres

The objective of our study was to incorporate and evaluate Silymarin, a chemically defined natural hepatoprotective agent, in lipid microstructured systems. Various constituents of lipid microspheres—namely, internal oily core; surfactant such as soyabean lecithin; and cosurfactants such as span 20, tween 20, tween 80, and propylene glycol—were tried in different concentrations to optimize the final formulation characteristics such as globule size range, structural integrity, sustainability, and percent drug-holding capacity. The final formulation (formulation A) was characterized with respect to size and morphology using transmission electron microscopy and laser diffraction technique. The enhanced mean percent release of 56.70 ± 2.03% was observed in 36 hr from silymarin-loaded lipid microspheres (formulation A), as compared to 18.67 ± 0.192% with silymarin solution (formulation B). Thus, a stable delivery system having synergistic hepatoprotective effect of silymarin and soyabean lecithin could successively be produced for passive targeting to the liver.     

Topical Anti-Inflammatory Potential of Quercetin in Lipid-Based Nanosystems: In Vivo and In Vitro Evaluation

Purpose

To develop quercetin-loaded phospholipid vesicles, namely liposomes and PEVs (Penetration Enhancer-containing Vesicles), and to investigate their efficacy on TPA-induced skin inflammation.

Methods

Vesicles were made from a mixture of phospholipids, quercetin and polyethylene glycol 400 (PEG), specifically added to increase drug solubility and penetration through the skin. Vesicle morphology and self-assembly were probed by Cryo-Transmission Electron Microscopy and Small/Wide Angle X-ray Scattering, as well as the main physico-chemical features by Light Scattering. The anti-inflammatory efficacy of quercetin nanovesicles was assessed in vivo on TPA-treated mice dorsal skin by the determination of two biomarkers: oedema formation and myeloperoxidase activity. The uptake of vesicles by 3T3 fibroblasts was also evaluated.

Results

Small spherical vesicles were produced. Their size and lamellarity was strongly influenced by the PEG content (0%, 5%, 10% v/v). The administration of vesicular quercetin on TPA-inflamed skin resulted in an amelioration of the tissue damage, with a noticeable attenuation of oedema and leukocyte infiltration, especially using 5% PEG-PEVs, as also confirmed by confocal microscopy. In vitro studies disclosed a massive uptake and diffusion of PEVs in dermal fibroblasts.

Conclusions

The proposed approach based on quercetin vesicular formulations may be of value in the treatment of inflammatory skin disorders.     

Topical Formulations Containing Finasteride. Part I: In Vitro Permeation/Penetration Study and In Vivo Pharmacokinetics in Hairless Rat

In hair follicle (Hf) cells, the type-2 5-α-reductase enzyme, implicated in androgenetic alopecia, is selectively inhibited by finasteride (FNS). Because an effective topical formulation to deliver FNS to Hf is currently unavailable, this investigation aimed at evaluating in vitro FNS skin permeation and retention through and into hairless rat and human abdominal skin. Four hydroxypropyl chitosan (HPCH)-based formulations (P-08–012, P-08–016, P-08–063, and P-08–064) and one anhydrous formulation without HPCH (P-10–008) were tested. The pharmacokinetics in plasma and skin after application of P-08–016 or P-10–008 on dorsal rat skin with single and repeated doses was investigated. P-08–016 performed the best in driving FNS to the reticular dermis without producing a high transdermal flux. Neither the in vivo single nor the repeated dose experiments produced plasma levels of FNS and no differences were found between formulations concerning skin retention. No increase in the amount of drug retained in the skin was obtained with the repeated dose experiment. In conclusion, the HPCH-based formulation P-08–016 might represent an alternative to systemic therapy for its ability to promote a cutaneous depot of FNS in the region of hair bulbs, minimizing systemic absorption even after repeated treatments. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2307–2314, 2014     

Effect of Concentration and Degree of Saturation of Topical Fluocinonide Formulations on In Vitro Membrane Transport and In Vivo Availability on Human Skin

Purpose. The thermodynamic acitvity of drugs in topical vehicles is considered to significantly influence topical delivery. In vitro diffusion across a synthetic membrane was shown to be correlated to the degree of saturation of the drug in the applied vehicle and therefore offers a potential for increased topical drug delivery. Fluocinonide a topical corticosteroid, was chosen as a model compound to investigate in vitro and in vivo availability from formulations with different degrees of saturation. Methods. Sub-, as well as, supersaturated drug solutions were prepared using PVP as an antinucleant agent. In vitro membrane diffusion experiments across silicone membrane and in vivo pharmacodynamic activity assessments, using the human skin blanching assay, were carried out. Results. Over the concentration range studied, the in vitro membrane transport of fluocinonide was proportional to the degree of saturation of the respective formulations. The in vivo pharmacodynamic response in the human skin blanching assay was related to the concentration of the drug in the vehicle irrespective of the degree of saturation. Conclusions. From the membrane permeation experiment it can be concluded, that the drug flux might be increased supra-proportionally with increasing donor concentration, drug (super-)saturation (proportional), beyond what would be anticipated based on ideal donor concentration and partition coefficient considerations only. These findings could not be confirmed in the in vivo investigation, probably due to additional vehicle effects (e.g., enhancement, irritation, drug binding) which have to be expected and could have altered the integrity of the stratum corneum and therewith topical bioavailability of the drug.     

Formulation,Characterization, and In Vitro Evaluation of Bioadhesive Gels Containing 5-Fluorouracil

The objective of this study was to prepare and evaluate in vitro the bioadhesive gels of 5-Fluorouracil (FU) for the treatment of oropharyngeal cancer. In preformulation study, the physicochemical interactions between FU and polymers were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrophotometry, and differential scanning calorimetry (DSC). According to FTIR, XRD, and DSC studies, the drug did not show any evidence of an interaction with the polymers used and was present in an unchanged state. The gel formulations containing FU were prepared by using Poloxamer 407, HPMC K 15 M, and Gantrez® S-97 (polymethylvinylether-co-maleic anhydride). The formulations contained Poloxamer 407 (16–18% w/w) either alone or in combination with HPMC K 15 M and Gantrez® S-97. The bioadhesiveness of the gels was found to increase with increasing proportion of HPMC K 15 M and Gantrez® S-97. In vitro release studies indicated that release could be sustained up to 8 hr. The permeability coefficients (Kp) of gel across cellulose membrane and buccal mucosal membrane were 1.06 × 10^?4 cm/s and 3.94 × 10^?5 cm/s, respectively, and differed significantly (p < 0.05). Increasing temperature increased the drug release by increasing drug diffusion despite increase in viscosity. The pH of the release medium showed a very slight effect on the release of FU. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer–Peppas model and the drug release kinetics primarily as non-Fickian diffusion.     

Preparation,In Vitro Characterization,and In Vivo Pharmacokinetic Evaluation of Respirable Porous Microparticles Containing Rifampicin

This study aimed to prepare and evaluate rifampicin microparticles for the lung delivery of rifampicin as respirable powder. The microparticles were prepared using chitosan by the spray-drying method and evaluated for aerodynamic properties and pulmonary drug absorption. To control the drug release, tripoly-phosphate in different concentrations 0.6, 0.9, 1.2, and 1.5 was employed to get a sustained drug release profile. The microparticles were evaluated for drug loading, % entrapment efficiency, tapped density, morphological characteristics, and in vitro drug release studies. Aerosol properties were determined using the Andersen cascade impactor. Porous microparticles with particle sizes (d_0.5) less than 10 μm were obtained. The entrapment of rifampicin in microparticles was up to 72%. In vitro drug release suggested that the crosslinked microparticles showed sustained release for more than 12 hrs. The drug release rate was found to be decreased as the TPP concentration was increased. The microparticles showed a fine particle fraction in the range of 55–63% with mass median aerodynamic diameter (MMAD) values below 3 μm. The in vivo pulmonary absorption of the chitosan microparticles suggested a sustained drug release profile up to 72 hrs with an elimination rate of 0.010 per hr. The studies revealed that the spray-dried porous microparticles have suitable properties to be used as respirable powder in rifampicin delivery to the lungs.     

Development of CD133 Targeting Multi-Drug Polymer Micellar Nanoparticles for Glioblastoma - In Vitro Evaluation in Glioblastoma Stem Cells

Pharmaceutical Research - Glioblastoma (GBM) is a malignant brain tumor with a poor long-term prognosis due to recurrence from highly resistant GBM cancer stem cells (CSCs), for which the current...     

Sterically Stabilized Liposomes Incorporating the Novel Anticancer Agent Phospho-Ibuprofen (MDC-917): Preparation, Characterization, and In Vitro/In Vivo Evaluation

Purpose

To incorporate phospho-ibuprofen (P-I), a lipophilic, water insoluble novel anti-cancer agent, into pegylated liposomes and upon formulation optimization to evaluate its antitumor activity in vitro and in vivo.

Methods

P-I loaded liposomes were prepared using the thin-film hydration method, and characterized for size, zeta potential, drug content and drug release. We examined their physical stability by particle size changes; their lyophilization ability in the presence of cryoprotectants; and their antitumor activity in vitro in human cancer cell lines and in vivo in a xenograft murine model.

Results

P-I was successfully loaded into liposomes consisting of soy-PC and PEG₂₀₀₀-PE. These liposomes were <150?nm in diameter; exhibited prolonged stability in suspension and can be lyophilized using sucrose as cryoprotectant. P-I liposomes inhibited the growth of human cancer cell lines in vitro and in vivo of xenograft in nude mice to a greater extent than free P-I.

Conclusions

High levels of P-I can be incorporated into liposomes which can be lyophilized in the presence of sucrose and showed good stability upon storage. Moreover, these drug-incorporating liposomes were capable of inhibiting the growth of xenografted tumors in mice more effectively than free P-I. These results justify further development of the P-I liposomes.     

Controlled Release of a Contraceptive Steroid from Biodegradable and Injectable Gel Formulations: In Vitro Evaluation

Purpose. The purpose of this study was to investigate the effects of formulation factors including varying wax concentration, drug loading and drug particle size, on drug release characteristics from both pure oil and gel formulations prepared with a combination of derivatized vegetable oil (Labrafil 1944 CS) and glyceryl palmitostearate (Precirol ATO 5), using levonorgestrel as a model drug. Methods. The effects of varying drug loadings, different drug particle sizes, and wax (Precirol) concentrations on in-vitro drug release rates were evaluated, and the mechanisms of drug release from the gels were determined. Results. Zero-order drug release rates from the 10% Precirol gel formulations containing 0.25, 0.50 and 2.00% w/v drug loadings were lower than those observed for oil formulations containing identical drug loadings. Higher zero-order release rates were observed from formulations containing smaller drug particles suspended in both oil and gel formulations. The mechanism of drug release from gels containing less than 0.25% w/w drug was diffusion-controlled. Increasing the wax concentrations in the gels from 5% w/w to 20% w/w significantly decreased the diffusivity of the drug through the gel formulations and markedly increased the force required to inject the gels from two different sizes of needles. Conclusions. This study shows how modification of the physicochemical properties of the gel formulations by changing the drug particle size, wax concentration and drug loading, affects drug release characteristics from the system.     

Development of Estimation Methods of Skin Oxidation and Evaluation of Anti-Oxidative Effects of Genistein in Topical Formulations

The objective of the present study was to establish the method of measurement of hydrogen peroxide and to estimate the anti-oxidative effect of genistein in the skin. UVB induced skin oxidation and anti-oxidative effect of genistein formulations were evaluated by determining levels of hydrogen peroxide. The mechanism involved in the determination of hydrogen peroxide is based on a color reaction between ferric ion (Fe³⁺) and xylenol orange, often called FOX assay and subsequent monitoring of absorbance values of the reactant at 540 nm. The reaction was to some extent pH-dependent and detection sensitivity was greatest at pH 1.75. Genistein liposomal gel demonstrated better anti-oxidative effect with regard to lowering hydrogen peroxide levels elevated by UVB irradiation compared to genistein-suspended gel. A linear relationship has been observed between anti-oxidative effect of genistein and drug deposition in the skin tissue. Genistein liposomal gel resulting in the localization of the drug in the deeper skin led to improved anti-oxidative effect compared to genistein gel. The suggested method for evaluation of oxidation of the skin can be used as a tool to screen effective anti-oxidative agents and their delivery systems acting on the skin.     

Formulation Development,Process Optimization,and In Vitro Characterization of Spray-Dried Lansoprazole Enteric Microparticles

This research focuses on the development of enteric microparticles of lansoprazole in a single step by employing the spray drying technique and studies the effects of variegated formulation/process variables on entrapment efficiency and in vitro gastric resistance. Preliminary trials were undertaken to optimize the type of Eudragit and its various levels. Further trials included the incorporation of plasticizer triethyl citrate and combinations of other polymers with Eudragit S 100. Finally, various process parameters were varied to investigate their effects on microparticle properties. The results revealed Eudragit S 100 as the paramount polymer giving the highest gastric resistance in comparison to Eudragit L 100-55 and L 100 due to its higher pH threshold and its polymeric backbone. Incorporation of plasticizer not only influenced entrapment efficiency, but diminished gastric resistance severely. On the contrary, polymeric combinations reduced entrapment efficiency for both sodium alginate and glyceryl behenate, but significantly influenced gastric resistance for only sodium alginate and not for glyceryl behenate. The optimized process parameters were comprised of an inlet temperature of 150°C, atomizing air pressure of 2 kg/cm², feed solution concentration of 6% w/w, feed solution spray rate of 3 ml/min, and aspirator volume of 90%. The SEM analysis revealed smooth and spherical shape morphologies. The DSC and PXRD study divulged the amorphous nature of the drug. Regarding stability, the product was found to be stable under 3 months of accelerated and long-term stability conditions as per ICH Q1A(R2) guidelines. Thus, the technique offers a simple means to generate polymeric enteric microparticles that are ready to formulate and can be directly filled into hard gelatin capsules.     

In Vitro and In Vivo Evaluation of Small Cationic Abiotic Lipopeptides as Novel Antifungal Agents

We investigated the antifungal potential of short lipopeptides against clinical fungal isolates with an objective to evaluate their clinical feasibility. All tested lipopeptides exhibit good antifungal activity with negligible difference between the MICs against susceptible and drug‐resistant clinical fungal isolates. The MTT assay results revealed the lower cytotoxicity of lipopeptides toward mammalian cells (NRK‐52E). In particular, LP24 displayed highest potency against most of the tested fungal isolates with MICs in the range of 1.5–4.5 μg/mL. Calcein dye leakage experiments with model membrane suggested the membrane‐active mode of action for LP24. Extending our work from model membranes to intact Aspergillus fumigatus in scanning electron micrographs, we could visualize surface perturbation caused by LP24. LP24 (5 mg/kg) significantly reduces the A. fumigatus burden among the various organs of infected animals, and 70% of the infected mice survived when observed for 28 days. This study underscores the potential of small cationic abiotic lipopeptides to develop into the next‐generation antimicrobial therapy.     

Design,Synthesis and In Vivo Anxiolytic Activity of Novel Flavonoids

Pharmaceutical Chemistry Journal - Worldwide millions of peoples are suffering from psychological disorders of which anxiety is one of the major and common problems. Knowing statistical reports of...