Two homopolymeric and three copolymeric additives for base oil were synthesized using octyl acrylate (OA) and tert-butyl acrylamide (TBA) monomers. The two additives named P1 and P2 are the homopolymers of TBA and OA, respectively, whereas copolymeric additives named Co1, Co2, and Co3 were synthesized by varying the ratios of TBA:OA as 1:3, 3:1 and 1:1, respectively. The prepared polymers were characterized by Fourier Transform Infrared (FTIR). Based on the solubility of synthesized polymers in base oil and reactivity ratios of TBA/OA copolymer (0.222, 0.434) calculated by Fineman-Ross method, P2, Co1, Co2 and Co3 were selected to evaluate their performance as pour point depressant (PPD), viscosity improver (VII), and anticorrosion addit
... Show MoreIn this work, some of new 2-benzylidenehydrazinecarbothioamide derivatives have been prepared by condensation of thiosemicarbazide and different substituted aromatic benzaldehydes in presence of glacial acetic acid to give compounds (1-6), these compounds have characterized by its physical properties and spectroscopic methods. This work also included theoretical study to prove the ability of these compounds as corrosion inhibitors; The program package of Gaussian 09W with its graphical user interface GaussView 5.0 had used for this purpose; the methods of Density Functional Theory (DFT) with basis set of 6-311G (d,p) / hybrid function of B3LYP and semiempirical method of PM3 have been used, the study included theoretical simulation
... Show MoreEconazole nitrate (EN) is considered as the most effective agent for the treatment of all forms of
dermatomycosis caused by dermatophytes. This study was carried out to formulate a stable
Econazole nitrate solution for a topical use through preparation of different formulas and selected
the most suitable one. The results indicated that the use of propylene glycol and ethanol as a vehicle
for EN which is very slightly soluble in water gave amore stable formula as EN topical solution,
with a shelf life of about 3.15 years .The data also indicated that the light accelerated the
degradation of EN, while the type of container (glass or plastic) had no effect on the rate of drug.
The overall results of this study suggest t
Many pharmaceutical molecules have solubility problems that until yet consist a hurdle that restricts their use in the pharmaceutical preparations. Lacidipine (LCDP) is a calcium-channel blocker with low aqueous solubility and bioavailability.
Lipid dosage forms are attractive delivery systems for such hydrophobic drug molecules. Nanoemulsion (NE) is one of the popular methods that has been used to solve the solubility problems of many drugs. LCDP was formulated as a NE utilizing triacetin as an oil phase, tween 80 and tween 60 as a surfactant and ethanol as a co-surfactant. Nine formulas were prepared, and different tests performed to ensure the stability of the NEs, such as thermodyna
... Show MorePropranolol is a nonselective-adrenergic blocker used in the treatment of hypertension, cardiac arrhythmias, and angina pectoris. A significant problem in propranolol therapy is that it undergoes extensive presystemic metabolism after oral administration leading to reduced bioavailability. In this study, two new propranolol derivatives have been designed, synthesized and characterized. These compounds were formed by acylation of propranolol followed by nucleophilic substitution reaction of acylated propranolol, these derivatives were analyzed for IR, CHN, melting points, and evaluated for their lipophilic properties compared with propranolol. The lower partition coefficient of these two derivatives revealed that the prodrug approach may be
... Show MoreIn this research, two drugs were bonded through amide and ester attachment, using lactic acid as aspacer binder, produced di pro drug such as Procain and Ciprofloxacin. Since Procain has ailocail anesthetic action and Ciprofloxacin as antibacterial drug was reacted with lactic acid produced ester compound (1), then the carboxylic acid of lactic acid could reacted with free Procain oil produced amide attachment, the controlled drug release in different pH values at 37C˚was studied to improve their characteristic and to minimize the side effect of the drug could be used in broad spectrum activity as atherapeutic material.This mutual prodrug was used with another biological active drug instead of single action. The prepared prodrug was charac
... Show MoreIsradipine related to dihydropyridine (DHP) class of calcium channel blockers (CCBs). It is used to treat hypertension, angina pectoris, as well as Parkinson disease. It goes under the BCS class II drug (low solubility-high permeability). The drug will experience extensive first-pass metabolism in liver, thus, oral bio-availability will be approximately15 to 24 %.
The aim of the study is preparing stable oral oil in water (o/w) nanoemulsion of isradipine to promote the colloidial dispersion of isradipine in the nano range, so that it may be absorded by intestinal lymphatic transport in order to avoid hepatic first-pass metabolism (israpidi
... Show MoreThis work is concerned with the vibration attenuation of a smart beam interacting with fluid using proportional-derivative PD control and adaptive approximation compensator AAC. The role of the AAC is to improve the PD performance by compensating for unmodelled dynamics using the concept of function approximation technique FAT. The key idea is to represent the unknown parameters using the weighting coefficient and basis function matrices/vectors. The weighting coefficient vector is updated using Lyapunov theory. This controller is applied to a flexible beam provided with surface bonded piezo-patches while the vibrating beam system is submerged in a fluid. Two main effects are considered: 1) axial stretching of the vibrating beam that leads
... Show MoreIn this paper, the Magnetohydrodynamic (MHD) for Williamson fluid with varying temperature and concentration in an inclined channel with variable viscosity has been examined. The perturbation technique in terms of the Weissenberg number to obtain explicit forms for the velocity field has been used. All the solutions of physical parameters of the Darcy parameter , Reynolds number , Peclet number and Magnetic parameter are discussed under the different values as shown in plots.