فهرست مطالب عنایت الله سلیمی

Background and

Minoxidil is one of the agents that can treat hair growth disorders, including alopecia, by increasing the anagen period. Due to the nature of minoxidil, the permeability of the drug to the skin surface is negligible. Therefore, the purpose of this study was to design and evaluate microemulsion formulations in order to increase skin permeability of minoxidil.

Microemulsions containing 2% minoxidil were prepared with an appropriate amount of oil phase, surfactant, and co-surfactant. The medicinal substance was dissolved in the oily phase. The physicochemical properties of the microemulsions, including particle size, viscosity, release, skin permeation through rat skin as well as the rate of drug permeation through rat skin, were evaluated using Franz cells.

The particle size of microemulsions was in the range of 5.45-10.4 nm, viscosity was 113.2-199.2 centipoise. This study showed that the parameters of drug release percentage in the second hour, drug release percentage in the 24th hour, viscosity and Dapp were significantly related to independent variables(P<0.05). Increasing the percentage of water and the percentage of oil has increased the amount of drug release in 24 hours. Increasing the percentage of oil and decreasing the percentage of water can lead to an increase in viscosity, and increasing the percentage of water can increase the amount of Dapp in microemulsions.

The prepared formulations were able to significantly increase the skin permeability of minoxidil.

A microemulsion is a stable, homogeneous pesticide formulation, based on an aqueous solvent, which is considered a suitable alternative to emulsion formulations. In this study, microemulsion formulations of cypermethrin insecticide were designed to control Aphis gossypii Glover (Hemiptera: Aphididae), one of the important pests of many crops and ornamental plants.  Xylene was selected as a suitable solvent based on the higher solubility of cypermethrin. Pseudo-ternary phase diagrams were constructed by the water titration method. The microemulsion system using mixtures composed of cypermethrin, Kenon 10+SDS surfactants, and 1-butanol cosurfactant had the highest microemulsion surface, and the ratio of 50:30:20 was chosen for further experiments. The physical and chemical properties of the obtained microemulsions were also evaluated. Microemulsion formulations were synthesized with 150 and 250 g/L a.i. (active ingredient) of the cypermethrin. The appearance of the microemulsion compounds was transparent and the droplet size of all samples was less than 35 nm. Foliar spraying of compounds including cypermethrin technical material (150 g a.i./L), cypermethrin technical material (250 g a.i./L), cypermethrin microemulsion (150 g a.i./L), and cypermethrin microemulsion (250 g/L a.i.), under greenspace conditions on Hibiscus rosa-sinensis L. (Malvaceae) caused 25.05, 37.54, 60.74, and 83.94% mortality on third instar nymphs 48 hours after treatment, respectively. Therefore, microemulsion formulations had significantly more insecticidal activity against A. gossypii compared to the technical material. In this study, an environment-friendly microemulsion system was designed to improve the efficacy of cypermethrin for controlling populations of A. gossypii. However, further research could be performed to assess the behavior and ultimate fate in the environment prior to commercialization.

Tadalafil has gained wide clinical acceptance in treatment of erectile dysfunction due to its long treatment window and lower potential for visual impairment. Transdermal drug delivery prevents systemic elimination, drug-drug and food-drug interactions, and reduces side effects by reducing the dose of the drug. The aim of this study was to evaluate the effect of microemulsion formulation on dermatological drug delivery of Tadalafil in rat skin.

In this laboratory study, Tadalafil microemulsions were prepared using a phase-diagram method with an appropriate ratio of oil and water mixture. Factorial design with three variables in two levels was performed to prepare eight formulations. Microemulsions containing 0.05 Tadalafil were prepared with an appropriate amount of oil phase (Oleic acid, Transcotol P), surfactant (Tween 80 and Span 20), and co-surfactant (Propylene Glycol). The drug was dissolved in the oil phase. The physicochemical properties of these microemulsions were evaluated using Franz Cells.

The droplet size of microemulsions ranged less than 60 nm and the viscosity ranged between 114.2 and 239.2 cpz. Parameters, including pH, drug release percentage in two hour and 24 hours, viscosity, Tlag and Dapp were significantly associated with independent variables (P<0.05).

The release kinetics of the drugs in selected microemulsions showed that compared to the Tadalafil solution, release occurs over time. All microemulsions significantly increase the flux coefficient and skin permeability.

Transdermal permeability refers to the delivery of medication to the body through the skin for local or systemic treatment. Transdermal drug delivery systems have not liver first pass effect and gastrointestinal adverse reaction. The use of chemical penetration enhancers and physical absorption systems are obsolete because there are expensive and changes of the skin structure, and the future look at the use of novel drug delivery systems. Nano-carriers is one of the most important new technologies in the field of novel drug delivery. Nanoparticle formulations have about 10 to 100 nanometers. Smaller particles are absorbing more easily than the surface of the skin.

In the present study, a review of previous studies on the use of Nano technology in transdermal drug delivery systems introduced them and their transdermal permeability was paid.

Nanotechnology in different routes and formulations has the ability to increase the permeability of therapeutic drugs depending on their characteristics, the physicochemical characteristics of the drugs, and the therapeutic goals one can choose.

Instability and deterioration of some drugs، vitamins and fatty dairy products in a liquid phase is one of the difficulties in the long-term storage، especially in the case of bulk products. Besides، some of these powder materials do have no enough compressibility to change them in a tablet dosage form and may need technological modification. In present study yogurt was used as a suitable model for the evaluation. Subjects and The liquid fresh yogurt was lyophilized at -40 and 0. 03 Tor pressure. The dry powder was homogenized by a 12 mesh size sieve. Carr’s compressibility index، Hausner ratio and the angle of repose tests were applied to evaluate porosity، density and therefore the flowability of yogurt powder. Study of deformation of particles during forcing was done by calculation of elastic recovery index. Carr’s compressibility index and Hausner ratio were 15% and 0. 94، respectively. The range of repose angle was between 19-20. The elastic recovery was obtained 60%. Hardness of tablets increased by decreasing compression velocity، therefore yogurt powder might have a plastic deformation. Tablets with low fat yogurt showed very good compressibility with 6-12 Strong-Cab hardness units. With respect to selection of the conditions and proper drying method (Liyophilization process)، and also to rely on measurable indexes such as: density، porosity and finally compressibility of the powder، preparation of a solid tablet from liquid yogurt for therapeutic and nutritious uses، is possible.

The goal of the present study was the preparation and evaluation of griseofulvin topical gel as a drug dosage form with appropriate efficacy and stability. To select the best formulation, formulations with different concentration of carbomer and HPMC were evaluated for their appearance. Then evaluated for physicochemical characteristics such as rheologic behavior, viscosity, stability and drug release. The result showed that the topical gel of griseofulvin prepared with Carbomer 0.5% and HPMC2.5% had good chemical stability, viscosity and drug release. The evaluation of the kinetic of drug release indicated that the formulations containing Carbomer 0.5% and HPMC 2.5% followed zero order release and liner Wagner, respectively. Rheologic data showed that while HPMC gel shows a very mild plastic behavior, Carbomer based gels behave very significantly as a thixotrop pseudo plastic gel. Rheologic behavior can affect the physicochemical and pharmacological aspects of the drug and plastic behavior of carbomer gel made it suitable for topical application. Although clinical research is necessary for Confirm the effectiveness but as a result, topical griseofulvin in a suitable formulation showed good drug release and efficacy.

Indomethacin is a NSAID (non-steroidal anti-inflammatory drug) that is used in treatment of pain and inflammatory. Immediate and sustained release products of this drug have side effects, so a proper replacement is needed. Use of the medicine via topical and cutaneous routs has advantages such as avoiding side effects on gastrointestinal; and supplying an amount of medicine in plasma for long time. The purpose of the present study was production and evaluation of the topical gel of indomethacin with an appropriate appearance and stability to reduce side effects especially on gastrointestinal and to deliver enough amount of the drug to target site. First the standard curve of indomethacin was plotted and then gels with different concentration of CMC and HPC was prepared. After the examination the appearance and stability of different formulations, the best formulations were chosen and rheology, stability and release experiments were done. 5% HPC and 2.5% CMC were chosen as the best percentages of these polymers to prepare formulation of indomethacin. Release drug from these formulations followed a first order rate and rheograms of both formulae showed a mild plastic behavior. According to the data obtained from the study, the best results were obtained with HPC polymer so that with increasing concentration, transparency and viscosity was much better but in concentration more than 5% the quality of the gels decreased.

Ibuprofen is a none-steroidal anti-inflammatory drug that is used for intensive to moderate inflammatory pains. This drug imposed some gastrointestinal (GI) disorders such as gastritis to the GI tract. Thus, preparation of Ibuprofen suppository especially for pediatrician who manage an anesthetic children with disability of swallowing or children sensitive to oral dosage forms is very useful. Besides, some difficulties with poor dissolution rate and bioavailability of the drug in the form of suppositories have been reported. Therefore, the aim of this study was to find an opportunity for solving the problem. In this study the effect of different quantities of drug (50,100 mg), of two sizes (60,100 m) in the base of Witepsol H15 and W35were used. Also, β-cyclodextrin in different concentrations of 5% and10% for enhancing solubility and colloidal silicon dioxide for uniformity of suppository drug content and Tween 80 with 0.25,0.5and 1 percent concentrations were used in consecutive tests. The results of different evaluations indicated, that, a better formulation could be prepared using Witepsol H15 with 100 mg Ibuprofen (60micron particle size),0.5%Tween 80,10% β-cyclodextrin and 0.5% colloidal silicon dioxide. The release of Ibuprofen in this formulation was 75% at 42.52min. Comparison of all formulations showed no significant difference in most parameters (P>0.05)excepting the formulation with Tween80 and β-cyclodextrin which showed a significant differences(P< 0.05) in drug release.

Sunscreen preparations are applied to protect the skin against harmful effects of sunshine. The most determining index for evaluation of these preparations is sun-protection factor (SPF), which reflects the degree of protection against UV light. Numerous in vivo and in vitro methods are employed for assessment. Despite the accuracy of in vivo methods, their expensiveness and time consuming have restricted their routine application at the stage of screening formulations. Therefore, in vitro methods are employed. In the present study, the efficacy of two in vitro methods (transpore and the diluted solutions methods) were compared using four trade preparations (Arden, Rasen, Onagrin and Rexol).Subjects and The first method was performed using a suitable, cheap and widely available substrate called transpore tape. In this method 2 mg/cm2 of each product was uniformly dispersed on the surface of the substrate, and the spectrophotomertic transmittance values in the range of 290 – 400 nm, at 5nm intervals, of prepared films were determined and values SPF were calculated. In the second method, different concentrations of test products were made in methanol and UV transmittance values were measured at the range of 292.5–337.5nm and values SPF were calculated. By plotting the amount of SPF versus each concentration the efficency of the products SPF were compared. The SPF of 2 mg/ml concentration of each product was calculated. In the first method results indicated a good, although incomplete, linear correlation between the measured and labelled (r = 0.975). In the second method all resulte were considerably larger than the labelled values and showed poor correlation (r = 0.35). Based on the results, because of the ease of process, availableness and also offering closer result with the in vivo mehtods. the transpore method, in contrast to the diluted solutions method, is a more efficient method for determination of SPF values. Therefore this method can be applied as an in–process control test to ensure lot-to-lot uniformity.