Preparation and Evaluation of Tretinoin Microemulsion Based on Pseudo-Ternary Phase Diagram

Purpose: The aim of the present research was to formulate a transparent microemolsion as a topical delivery system for tretinoin for the treatment of acne. Methods: Microemulsion formulations prepared by mixing appropriate amount of surfactant including Tween 80 and Labrasol, co-surfactant such as propylene glycol (PG) and oil phase including isopropyl myristate – transcutol P (10:1 ratio). The prepared microemolsions were evaluated regarding their particle size, zeta potential, conductivity, stability, viscosity, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), refractory index (RI) and pH. Results: The results showed that maximum oil was incorporated in microemolsion system that was contained surfactant to co-surfactant ratio (Km) of 4:1. The mean droplets size range of microemulsion formulation were in the range of 14.1 to 36.5 nm and its refractory index (RI) and pH were 1.46 and 6.1, respectively. Viscosity range was 200-350 cps. Drug release profile showed 49% of the drug released in the first 8 hours of experiment belong to ME-7. Also, Hexagonal and cubic structures were seen in the SEM photograph of the microemulsions. Conclusion: physicochemical properties and in vitro release were dependent upon the contents of S/C, water and, oil percentage in formulations.Also, ME-7 may be preferable for topical tretinoin formulation

Enhanced Corneal Permeation of Pilocarpine Using Liposome Technology

A novel liposomal pilocarpine formulation as an ophthalmic drug delivery system has been designed to treat patients with glaucoma. The purpose of the present study was to formulate and evaluate liposomes loaded with pilocarpine and to evaluate permeation through rabbit cornea. Liposomes containing pilocarpine were prepared using thin film method. The quantities of soya lecithin and cholesterol were changed to enhance the encapsulation of the drug. The physicochemical properties of the prepared liposomes were evaluated according to their viscosity, pH, particle size, in vitro drug release, and transcorneal rabbit permeation. Dialysis membrane method was utilized to assess drug release profile. The results indicated that the mean particle sizes of liposomes were 120.5-212 nm and the pH and viscosity of formulations were in the range of 6.30-6.63 and 43.85-80.1 cps, respectively. According to the release study results, maximumally 60% of the drug released from liposomal formulations after 24 hours of the experiment. Also, the cumulative percentage of the drug permeated through rabbit cornea was differing from 3.86 to 14.9%. Irrespective from the composition and characteristics of the different liposomal formulations, they significantly increased the drug partitioning, permeability coefficient and flux of pilocarpine in rabbit cornea ex vivo model in comparison to control drug solution. The present study proved that any alteration in composition and nature of pilocarpine liposomal formulations may affect the drug permeability parameters through corneal membrane and also physico-chemical properties. It is probably due to the change in corneal structure in the presence of different liposomes composition

Targeted Nano-Drug Delivery System to Colon Cancer

Cancer has been considered as the most cause of death in world. Employing of nanocarriers as drug delivery systems provide a platform for delivering drugs with increasing the anti-cancer efficacy, enhancing bioavailability of drugs, reducing side effects, enhancing the circulation half-life of drugs, improving the distribution of drugs and overcoming drug resistance. A number of nanocarriers have been studied as drug delivery systems for improving the treatment of cancer including liposomes, micelle, polymeric nanoparticles, carbon nanotubes, dendrimers, solid lipid nanoparticle (SLN) and nanostructure lipid carrier (NLC). In order to enhance recognition and internalization of nanocarriers by the target tissues, their surfaces can be modified with targeting ligands such as integrins, transferrin, folic acid, polysaccharides and antibodies. In this chapter, we are going to introduce the targeted nanocarriers for improving the cytotoxic action of drugs with further attempt of decreasing dose to achieve higher anticancer activity. Targeted nanocarriers would provide a promising therapeutic approach for cancer

Preparation and Microstructural Characterization of Griseofulvin Microemulsions Using Different Experimental Methods: SAXS and DSC

Purpose: The objective of the present study is to formulate and evaluate a new microemulsion (ME) for topical delivery of griseofulvin. Methods: The solubilities of griseofulvin in different combinations of surfactant to co-surfactant (S/Co ratio) were determined. Accordingly, based on their phase diagrams, eight microemulsions were formulated and then evaluated with respect to their particle size, surface tension, viscosity, conductivity, zeta potential and stability. Their release behavior, Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), refractory index (RI), pH and Small-angle-X-ray scattering (SAXS) were also assessed. Results: The results indicated that the mean droplet size of the MEs ranged from 30.9 to 84.3 nm. Their zeta potential varied from -4.5 to -20.8. Other determined characteristics were viscosity: 254-381 cps, pH: 5.34-6.57, surface tension: 41.16- 42.83 dyne.cm-1, conductivity: 0.0442 – 0.111 ms.cm-1. The drug release was in the range of 22.4 to 43.69 percent. Also, hexagonal, cubic and lamellar liquid crystals were observed in SAXS experiments. Conclusion: It can be concluded that any alteration in MEs constituents directly affects their microstructure, shape, droplet size and their other physicochemical properties

Comparative Study of Modified Chlorhexidine Toxicity, Chlorhexidine and Sodium Hypochlorite on Gingival Fibroblast Cells L929 In Vitro

One obvious and good properties of sodium hypochlorite is capacity of tissue solubility which has effective role in direct root canal cleaning, necrotic tissues and root canal system complexity. Chlorhexidine, in spite of all advantages that have than sodium hypochlorite, lacks this property. Superficial active factors or surfactants are materials that are used extensively as irritant, emulsifier, disinfection and solution additive. Surfactants are different types including benzalkonium chloride 4% and sodium lauryl Sulfate 2%. In this research, sodium dodecyl sulfate was used. Gingival fibroblast cells are kept in 25 cm2 flasks in 370C temperature. And then they are cultivated in Gibco Dulbecco’s Modified Eagle Medium (DMEM). 96 wells plates with 50 microliter are filled with growth medium with 2000 fibroblast and it is placed in incubator for 24 hours. After 24 hours, growth medium is thrown away and all plates are washed with phosphate buffered saline (PBS). All experimental steps are performed for preventing samples being contaminated under hood. The experiment was carried out as triplicate (3 wells cell). Results: In order to perform a research, Tukey-test and Duncan test were applied for explaining research variable. Results: toxicity rate of under tested solutions on fibroblast cells for group 1-4 are respectively (right to left) 13.75, 51.75, 20.75 and 51.75. Results of comparing means in four groups in landa level 4 indicated that groups are not significantly different in toxicity rate. results of this research indicated that this mixture can be used as an appropriate candidate for replacing sodium hypochlorite based on its disadvantages which needs to be studied more

The Potent In Vitro

Archaeosomes are a new generation of liposomes that exhibit higher stabilities under different conditions, such as high temperatures, alkaline or acidic pH, and presence of bile salts in comparison with liposomes, and can be used in biotechnology including drug, gene, and vaccine delivery. The objective of this study was to prepare archaeosomes using lipid extracted from Sulfolobus acidocaldarius and evaluate their physicochemical properties. The lipids were extracted from S. acidocaldarius and assayed by High Performance Thin-Layer Chromatography (HPTLC). Archaeosomes were prepared using film method and methylene blue was used as drug model. They were characterized for their vesicle size and Differential Scanning Calorimetry (DSC) was used to investigate changes in their thermal behavior. The released amount of methylene blue was determined using a dialysis membrane and rat skin. HPTLC analysis of the extracted lipids showed that glycerol ether may be the major lipid with more than 78 percent probability. Results of particle size determination showed a mean size of 158.33 nm and the results of DSC indicated the possible interaction of methylene blue with lipids during the preparation of archaeosome. The addition of cholesterol significantly improved the encapsulation of methylene blue in the archaeosome so that the encapsulation efficiency was 61.66 ± 2.88%. The result of in vitro skin permeation showed that methylene blue could pass through skin model according to Peppas model and there was about 41.66% release after 6 h, whereas no release was observed through dialysis membrane. According to the results of the study, it is concluded that archaeosome may be successfully used as drug delivery system

IN VITRO SCREENING OF ANTI-CANDIDA ACTIVITY OF SAPONINS EXTRACTED FROM GLYCYRRHIZA GLABRA AND QUILLAJA SAPONARIA

Objective: In recent years, the incidences of opportunistic fungal pathogens have increased and development of fungal resistance to antifungal drugs is a global concern. Therefore, it is important to identify new antifungal agents. Saponins are secondary metabolites that are found in various plant species and show antifungal activity. The aim of the study was to evaluate antifungal activity of saponin extracted from the Glycyrrhiza glabra against Candida species (Candida albicans, Candida tropicalic and Candida glabrata). Antifungal activity Quillaja saponaria total saponin (QST) was also evaluated. Methods: The roots of the plant were dried, powdered and def-fatted with petroleum ether in a soxhlet apparatus. The air dried powder was successively extracted with methanol, n-butanol and diethyl ether. The antifungal activity of the saponins was carried out using well diffusion method and also the value of minimum inhibitory concentrations (MIC) was calculated. Clotrimazole was used as positive controls to determine the sensitivity of the species. Results: According to the results, C. albicans, and C. tropicalic were sensitive to the saponins of G. glabra, and Q. saponaria, while saponin isolated from G. glabra just could inhibited the growth of C. glabrata. Conclusion: In vitro studies have demonstrated that saponins extracted from G. glabra, and Q. saponaria can serve as potential candidates for the development of new antifungal agents.     Key words: Saponin, Glycyrrhiza glabra, Quillaja saponaria, Anti-Candida activit

Formulation of a New Generation of Liposomes from Bacterial and Archeal Lipids

Purpose: To evaluate the application of bacterial liposomes and archaeosomes as a novel drug delivery system for in vitro cytoplasmic delivery of molecules into cancer cells.Methods: Bacterial membrane lipids were extracted using chloroform and methanol. Bacterial liposomes and archaeosomes of E. coli, Acidianus brierleyi and Sulfolobus acidocaldarius were prepared using film method and their trailing in cancer cells (HT-29) was evaluated by carboxyfluorescein (CF). Their morphological characteristics were assessed by atomic force microscopy (AFM).Results: At 37 °C, the liposomes and archaeosomes interacted with cell membranes predominantly by fusion and endocytosis. The AFM images showed uniform and dispersed distribution of the liposomes.Conclusion: The findings demonstrate that bacterial liposomes and archaeosomes may be useful as drug delivery carriers for the treatment of cancer.Keywords: Liposome, Archaeosome, E. coli, Acidianus brierleyi, Sulfolobus acidocaldarius, Cancer, HT-29 cell, Atomic force microscopy, Film metho

Histological Evaluation of Wound Healing Effect of Topical Phenytoin on Rat Hard Palate Mucosa

Extension and duration of wound healing following periodontal surgery are very important. The aim of present study was histological evaluation of wound healing of topical phenytoin on rat hard palate mucosa. A total of 60 rats were randomly divided into four groups of 15(n=15). A standard 4×6 mm diameter wound was created on the hard oral palate of each rat. The control group were given an equal volume of normal saline. The group of phenytoin and chitosan gel received the topical gel of phenytoin and chitosan, respectively. The fourth group were received a dosage of 10mg phenytoin daily. Five rats each were sacrificed and all sections were examined for histologic changes by light microscopy. The mean number of neutrophils, fibroblasts, macrophages, epithelialization, and the density of collagen fibers were evaluated in each group. Data were analyzed using ANOVA and Kruskal-Wallis tests. The number of fibroblasts and the rate of epithelialization in the group of phenytoin gel were significantly higher on the 7th day than the control group (P <0.05). The density of collagen fibers on the 14th day was significantly higher in the group of phenytoin gel than the control group (P <0.05). It can be concluded that topical phenytoin to promote wound healing of rat hard palate

Utilization of thin film method for preparation of celecoxib loaded liposomes

Purpose: Celecoxib is nonsteroiddal anti-inflammatory drug that has been used extensively to treat patients with arthritis. The aim of the present study was to formulate and characterize liposomal vesicles loaded with celecoxib. Methods: Liposomes were prepared by thin film method using soya lecithin and cholesterol. The release of drug was determined using a dialysis membrane method. Liposomes were characterized by Differential Scanning Calorimetery (DSC), Transmission Electron Microscopy (TEM) and their particle size was also determined. Results: The results showed that the drug encapsulation efficiency was 67.34% and there was 67.16% release after 0.5, 1, 2, 3, 4, 5, 6, 7, 8 and 24 h. Results of particle size determination showed a mean size of 677nm and nanoparticles were spherical as shown by TEM. The DSC curve of lecithin, cholesterol and celecoxib were different from celecoxib containing liposome. Conclusion: The results of characterization of the vesicles indicated the potential application of celecoxib loaded liposome as carrier system