Sulphuric Acid Corrosion of Mild Steel in Leave Extracts of Cnidoscolus aconitifolius Plant

Alkaloid and nonalkaloids extracts of Cnidoscolus aconitifolius leaves is reported as corrosion inhibitor of mild steel in HCl. Conventional weight loss measurements and Tafel polarization techniques are employed to study the effect on mild steel corrosion in H2SO4 solutions. The weight loss result revealed that both plant extracts are excellent corrosion inhibitors. Electrochemical polarization data revealed that mixed mode of inhibition. The increase in %IE with change in concentration of the extracts suggests the strong adsorption of active molecules leading to the formation of a protective layer on the mild steel surface.  It was found that adsorption of both leaf extracts followed Langmuir adsorption isotherm model. Keywords: Weight loss, Langmuir isotherm, activation energy, corrosion current density, inhibition efficiency, Cnidoscolus aconitifolius

Inhibition and Adsorption impact of Leave Extracts of Cnidoscolus Aconitifolius on Corrosion of Aluminium Sheet in 1 M Hcl Medium

Corrosion inhibition in the presence of alokaloid and non alkaloid extracts of Cnidoscolus aconitifolius in 1M HCl was studied using the weight loss and hydrogen evolution techniques at 303, 313 and 333 K. The results obtained revealed that the inhibition efficiency decreased with increase in temperature. Inhibition occurred through adsorption of the alokaloid and non alkaloid extracts molecules on the metal surface. The apparent activation energies, enthalpies and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined and discussed. The fundamental thermodynamic functions were used to evaluate important inhibitive properties of Cnidoscolus aconitifolius.Keywords: Activation energy; Gibb’s Free Energy; Langmuir adsorption; Cnidoscolus aconitifolius; Aluminium sheet

FORMULATION AND IN-VITRO EVALUATION OF THEOPHYLLINE HYDROCHLORIDE EFFERVESCENT FLOATING TABLETS: EFFECT OF POLYMER CONCENTRATION ON TABLET BUOYANCY

Objective: This study was undertaken to formulate a floating drug delivery system of theophylline hydrochloride using different concentrations of a chosen polymer and then investigate how polymer concentration affects buoyancy and drug release properties of the tablets. Methods: Hydroxypropyl methylcellulose (HPMC) at different concentration levels of 15% (F1), 20% (F2) and 30% (F3) was used to form the three formulation batches of floating tablets. Wet granulation method was used for the granule preparation while Sodium bicarbonate and citric acid were used as the gas generating agent. The physical properties of the granules and the floating tablets were evaluated. Also determined were the physicomechanical properties, buoyancy and swelling characteristics of the tablets. The in vitro drug release study was carried out according to the USP I (basket method) for 8h in 900 ml 0.1N HCl at 50 rpm. Samples withdrawn at the regular predetermined time were analyzed spectrophotometrically at a wavelength of 271 nm and data obtained statistically analyzed by one-way analysis of variance (ANOVA). The differences between means were considered significant at P<0.05. Results: The result showed that polymer (HPMC) concentration significantly (p>0.05) increased swelling index and improved floating lag time, it had no significant effect on the total floating time. Percentage drug release at the end of 8 h was 100%, 98.2% and 96.13% for formulation F1, F2 and F3, respectively. All three formulations followed the Higuchi drug release kinetics model and the mechanism of drug release was the non Fickian diffusion with exponents of 0.46, 0.51 and 0.56 for the respective batch. Conclusion: Batch F3 gave a better-controlled drug release and floating properties in comparison to batch F1 and F2 thus Polymer concentration influenced the onset of floating and controlled the release of Theophylline

PRELIMINARY INVESTIGATIONS INTO THE PHYSICOCHEMICAL AND COMPACTION CHARACTERISTICS OF MODIFIED STARCH OF DISCOREA ALATA USING DICLOFENAC SODIUM TABLET

Objective: This work focused on evaluating the micromeritic and compressional properties of pregelatinized African water yam (Discorea alata) starch and its modified forms with comparison to pregelatinized corn starch and microcrystalline cellulose.Methods: Two modifications of the water yam starch were prepared; acetone dehydrated pregelatinized form (DSA) and an admixture of DSA and pregelatinized corn starch (CDSA). A third form of starch is the acetone dehydrated pregelatinized corn starch (CSA). These were used to form batches compacted as tablets using diclofenac sodium as the active moiety. Physicochemical and flow characteristics of the starch powders were elucidated, and the drug starch compatibility studies done using the Fourier transform Infra-red (FTIR) technique. Compaction studies were investigated on tablets formed at different compression pressures and Heckel plots were prepared.Results: The slope of the straight line (K) of 0.8959 was greatest for F1 while yield pressure (Py) value of 10.965 was highest for F3. These values from the Heckel plot suggest that while the tablets of control batch of microcrystalline cellulose (F4) and a batch of pregelatinized corn starch (F2) formed harder compacts, less likely deformed plastically, the Discorea alata batch (F1) and the admixed batch (F3) were likely to deform plastically. Also, the binding efficiency of the compact was significantly high (47.81%Kgscm-1) for F4 at 56.5Kpas compaction pressure, higher than that obtainable for any of the other formulations at the compaction pressures under consideration. All starches formed had similar moisture content (of 10%) despite the different sources but the interaction between the water molecule and pregelatinized water yam starch improved as revealed by viscosity(7.18mPas), hydration capacity(3.27%) and swelling index (250%) of CDSA.Conclusion: It could be concluded that pregelatinized water yam starch could be used as a substitute for corn starch or microcrystalline cellulose as a pharmaceutical excipient (binder/filler) in tablets formulation

Plants as pharmaceutical excipients in oral sustained drug delivery systems: A review

Plants and their derivatives have contributed immensely to drug development for their application as medicinal agents or as excipients in preparation of new drug delivery systems. Their use keeps increasing by the day. The rich, yet-to-be fully tapped vegetation available in the African sub-region puts it with great potential to be the next global destination as sources for pharmaceutical excipient. This work reviews published articles on plants and derivatives that have been employed so far in modifying drug delivery. Published articles from databases of PubMed, science direct and google scholar were sourced. Obtained manuscripts were screened for relevance to the topic and currency from reading through the abstract and scanning the body of the work. Gums and mucilages as plant derivatives in their natural form or as changed forms have been well investigated for use in controlled drug delivery. Some of these have been as functional in modifying drug release as many commercially employed excipients in drug delivery. Many plants and plant-derived polymers are generally regarded as safe, easily cultivated, show good functionality as drug additives and can be modified to improve on any less desirable property. Taking advantage of these positive factors will open doors for optimal use of these naturally endowed pharmaceutical excipient

Heavy metal contamination of green leafy vegetable garden in Itam road construction site in Uyo, Nigeria. Research journal of environmental and earth sciences 4(4

Abstract: Human exposure to heavy metals is a subject of public health concern that have attracted the attention of researchers, health and nutrition experts all over the world. Green Leafy Vegetables (GLVs) are important part of diets in the South-South Region of Nigeria. Consumption of vegetables exposed to heavy metals contamination may lead to serious health complications. In this investigation, we estimated the concentrations of some heavy metals (Pb, Hg, Al, Cd, Fe and Zn) in GLVs harvested from vegetable gardens in the residential areas along Itam road construction site, Uyo, Nigeria. The results showed that Pb, Hg, Al and Cd concentrations were significantly high (p<0.05) in all exposed GLV samples than the control but Teliferia occidentalis had higher values of heavy metals than Talinium triangulare. However, zinc and iron levels in the GLV exposed samples were not significantly (p>0.05) higher than the control. Our findings showed that heavy metal contamination of edible vegetable is high at road construction sites and may impact negatively on the health of human and animals living in such environment. We suggest that health impact assessment be carried out at construction sites in order to suggest necessary measure that can alleviate the effects of such environmental contaminants