Biomedical subjects

M U Adikwu

Publications and source records attributed to M U Adikwu.

29 records · Page 2Linked to original sources

PubMedDate not supplied

Bioadhesive delivery of hydrochlorothiazide using tacca starch/SCMC and tacca starch/Carbopols 940 and 941 admixtures.

Tacca starch and its admixtures with Carbopols 940 and 941; and sodium carboxymethylcellulose (SCMC) were evaluated for bioadhesive delivery of hydrochlorothiazide into the gastrointestinal tract (GIT). The bioadhesive properties were evaluated using the adhesion of polymer-coated glass beads on the antrum region of the porcine gastrointestinal tract and Lecomte Du Nouy tensiometer. The swellings and release characteristics of the films/hydrogels of tacca starch and its admixtures were also studied. Results of the bioadhesive properties indicated that although tacca starch is a poor bioadhesive biopolymer at low concentration, the admixtures showed improved bioadhesive properties. The swelling and the release characteristics also confirmed that the admixtures could be used for bioadhesive drug delivery into the GIT.

Acrylic Resins↗

PubMedDate not supplied

Detection of halofantrine, mefloquine and proguanil by charge--transfer complexation on thin layer plates.

A complexation phenomenon between certain antimalarials (as donors) and chloranilic acid (as an acceptor) has been studied using thin-layer-chromatography (TLC). The antimalarials were subjected to charge--transfer complexation using chloranilic acid as the pi-acceptor. This technique was used for the qualitative detection of the drugs. Drug-spotted TLC plates, when developed in suitable solvent systems and sprayed with the pi-acceptor gave a spontaneous purple colour. The Rr values of the three drugs were found to be constant and specific for each drug sample in a particular solvent system.

Antimalarials↗

PubMedDate not supplied

Evaluation of Prosopis africana gum in the formulation of gels.

Prosopis africana gum was evaluated for use in the formulation of gels. The rate of release of salicylic acid from gels prepared from prosoopis gum was investigated. The rate of permeation of the drug through the gel was also evaluated. Surfactants were incorporated into the gels and the effect on the release and permeation was also investigated. Tragacanth gum gel was also prepared and used as the standard. The release and permeation of the drug from the gel was low. Incorporation of surfactants did not enhance the release of the drug. However the low release and permeation rates may be due to the poor water solubility of the incorporated drug. Correlation of the quantity of drug released with viscosity shows that drug release was dependent on the viscosity of the gels; the highly viscous gels showed slower release rates.

Excipients↗

PubMedDate not supplied

Properties of films prepared from prosopis and mucuna gums.

Various properties of the films prepared from mucuna and prosopis gums have been evaluated. Sodium carboxymethylcellulose was used for comparison. When studied for elongation at break point, the most elastic of the gums was prosopis gum, followed by sodium carboxymethylcellulose, while mucuna gum was the least elastic. On microscopy, prosopis and sodium carboxymethylcellulose formed films of equal consistency without pores.

Biological Factors↗

PubMedDate not supplied

Effect of dissolution fluid and presence of hog intestinal barrier on the dissolution of theophylline from bioadhesive granules.

The effect of dissolution fluid and the presence of a natural barrier (hog intestine) on the release of theophylline from some bioadhesive granules is presented. A higher quantity of the drug was released in simulated intestinal fluid (SIF) than O. IN HCl. When a hog intestine was used as the diffusion barrier, the availability of the drug through the barrier into the sink solution was low, ranging from 20-35%.

Adhesives↗

PubMedDate not supplied

Evaluation of the physico-chemical properties of a new polysaccharide gum from Prosopis africana.

The gum obtained from the ripe seeds of Prosopis africana was processed to compendial standard for plant gums and characterised. Toxicological studies of the polysaccharide on mice showed the material to be safe. The material hydrates slowly in aqueous media to form a colloidal dispersion. Swelling studies on the gum shows that the gum has a higher swelling capacity than methylcellulose. Rheological studies showed that the material is more viscous than tragacanth gum at equivalent concentrations. Acid hydrolysis and thin layer chromatography of the resulting hydrolysates showed that the gum contains glucose, fructose, galactose and xylose as the monosaccharide components. Microbial tests showed the gum to contain 8.26 x 10(4) viable cells per gram when freshly prepared. Other properties of the gum evaluated includes; melting or charring temperature, optical properties, true density, ash values, element content as well as its reactions with lead subacetate solution and 0.02 M iodine.

Animals↗

PubMedDate not supplied

Studies of the complexation of chloranilic acid with proguanil.

Studies on the complexation between chloranilic acid and proguanil has been carried out. The chloranilic acid acted as a pi-electron donor. The stoichiometric relationship in the complex was determined by employing the Job's method of continuous variation. The results indicate that the complex exhibits a purple colour and absorbs maximally at 520 nm. Spectrophotometric studies show that the method could be useful in the analysis of proguanil.

Benzoquinones↗

PubMedDate not supplied

Drug adsorption studies on pregelatinized gladiolus starch.

A comparative evaluation of the adsorption properties of pregelatinized gladiolus starch and activated charcoal on such drugs as chloroquine phosphate, aspirin, ampicillin and caffeine has been made. Results indicate that the adsorption capacity increases with increase in concentration of adsorbent used. Pregelatinized gladiolus starch exhibited a higher complexation affinity for chloroquine phosphate than activated charcoal, while the reverse was observed in the case of aspirin. The adsorption of caffeine and ampicillin was insignificant with the adsorbents. The desorption profile was slower for the pregelatinized gladiolus starch than for activated charcoal. This slow release property might be exploited in formulations where sustained-release is the desired goal.

Adsorption↗

PubMedDate not supplied

Charge-oriented modelling in charge-transfer systems.

Various mechanisms are often used toxplain the charge-transfer interactions between various electron donors and acceptors. Commonly accepted mechanisms are those in witch the acceptors forms a weak interaction of the Lewis acid--Lewis base type. A modelling approach is applied in this study to examine this mechanism as well as other mechanism. A charge-oriented mechanism is proposed in solvent systems that may not favour this mechanism of interaction.

Chemical Phenomena↗

PubMedDate not supplied

Detection of alpha-methyldopa on thin-layer plates using pi-acceptors in 1,4-dioxane.

pi-Acceptors (P-chloranil and chloranilic acid) in 1,4-dioxane were used to detect alpha-methyldopa on thin layer plates. Thin layer plates coated to a thickness of 0.25 mm with silica gel G60 were spotted with solution of alpha-methyldopa from drug formulations and pure alpha-methyldopa solution. The plates were developed in a solvent system of methanol: glacial acetic acid: water (14:5:3). The developed plates were dried and sprayed with pi-acceptors, and further were counter-sprayed with dimethylformamide (DMF). P-Chloranil gave an immediate blue green complex with alpha-methyldopa which intensified on counter-sprayed with DMF. alpha-methyldopa (reference sample and those from drug formulations) gave Rf of 0.85 and excipients from the drug formulations did not interfere with the result.

Benzoquinones↗

PubMedDate not supplied

In vitro antimicrobial interactions of arthemeter with some 4-quinolones.

Bacterial infections often co-exist with acute malarial attacks. The effect of combining arthemeter (a new antimalarial) with some commonly used 4-quinolones (ciprofloxacin, pefloxacin, norfloxacin and nalidixic acid) was investigated in-vitro with a view to providing data for the design of drug regimens for the treatment of such infections. While arthemeter demonstrated no antibacterial activity whatsoever against any of the test microorganisms (E. coli and Staph. aereus), the 4-quinolones shared marked activity. Comparative analyses of the activity of each quinolone alone and in combination with arthemeter showed 0% 43.8%, 44.9% and -12.2% change in the minimum inhibitory concentration (MIC) of nalidixic acid pefloxacin, ciprofloxacin and norfloxacin respectively against E. coli and -17.5%, 22.3% 35.8% and 50.9% change in the MICs of the same respective drugs against Staph. aureus. These changes in MIC were statistically significant (Pf0.05). With respect to infections caused by E. coli and E. coli, the combination of artemether with ciprofloxacin or pefloxacin proves to be a rational chemotherapeutic regimen when such infection co-exist with malaria.

4-Quinolones↗