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Biomedical subjects

M A Moustafa

Publications and source records attributed to M A Moustafa.

At least 37 records · Page 2Linked to original sources
PubMed1975

Succinylsulfathiazole crystal forms. II: Effect of additives on kinetics of interconversion.

The effect of various additives on the rate of transformation of the metastable anhydrous succinylsulfathiazole Form I to the water-stable dihydrate Form II in aqueous suspensions was studied. Some structurally related compounds, viscosity-imparting agents, surfactants, and coloring agents were used as possible transformation retardants. The effect of including seeds of Form II in the presence and absence of additives is also discussed. Some additives, e.g., methylcellulose and phthalysulfathiazole, showed significant transformation-retarding effects. Other additives, e.g., sulfanilamide and glycerin, increased the rate of transformation. Coloring agents had only slight effects. Utilization of the results in the formulation of physically stable aqueous suspensions of succinylsulfathiazole is discussed.

Chemical Phenomena↗
PubMed1975

Succinylsulfathiazole crystal forms. III: Crystal growth studies.

Crystal growth accompanying the transformation of succinylsulfathiazole crystal forms in aqueous suspensions was studied using a projecting microscope. The effects of increase of temperature, agitation, inclusion of seeds of Form II (the water-stable dihydrate), sulfathiazole, methylcellulose, and polysorbate 80 on the particle-size distribution of anhydrous succinylsulfathiazole Form I were examined. Rates of crystal growth, calculated as increase of diameter per unit time, were given under different experimental conditions. Increase of temperature, agitation, and seeding with nuclei of Form II had significant growth-accelerating effects. Sulfathiazole and polysorbate 80 had growth-retarding effects. Methylcellulose inhibited the crystal growth of Form I for over a year. Aqueous suspensions of Form II did not show any change in particle-size distribution. The crystal growth was shown to be a direct consequence of the transformation of the crystal form. Physical conditions and additives which had accelerating or retarding effects on the rate of succinylsulfathiazole in aqueous suspensions.

Chemical Phenomena↗
PubMedDate not supplied

Arthroscopic examination of the femorotibial joints of horses.

A technique for satisfactory arthroscopic examination of the lateral and medial femorotibial joints of the horse is described. The entry portal is made between the middle and medial patellar ligaments with the horse on its back and the stifle flexed. This position allows easy access to view the intercondylar eminence of the tibia. From this reference point, examination of all but the most caudal and medial structures of the joints are possible by manipulating the sleeve and telescope and maintaining joint distention. In a series of 20 examinations, iatrogenic trauma was recognized only once.

Animals↗
PubMedDate not supplied

Polarographic determination of N-acetyl-L-cysteine in pharmaceutical preparations.

The polarographic behaviour of N-acetyl-L-cysteine in Britton Robinson Buffer (BRB) over the whole pH range was studied. At pH 10, a well-defined anodic wave was developed. The wave was irreversible, one-electron, diffusion-controlled and partially affected by adsorption phenomenon. Adopting both direct current (DCT) and differential pulse polarographic (DPP) modes, the current concentration plot is rectilinear over the range 0.05 to 1.0 mM and 0.01 to 0.75 mM, respectively, with a minimum detection limit of 0.0005 mM using the DPP mode. The proposed method was successfully applied to the determination of N-acetyl-L-cysteine in pharmaceutical preparations. The obtained results were in a good agreement with those obtained by the official method.

Acetylcysteine↗