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Tigernut starch is starch extracted from the tubers of Cyperus esculentus L. a perennial herb commonly known as tigernut. The effect of pH on the foaming, gelatinization, solubility, swelling, paste clarity, viscosity, freeze-thaw stability, and binder efficiency of the starch in buffer solutions of pHs 4, 7, and 9.2, representative of acid, neutral, and alkaline pHs were evaluated. Marked pH responsiveness was observed in all these parameters to varying degrees. The foaming capacity, paste clarity, freeze-thaw stability, swelling, and viscosity increased while only the gelatinization temperature decreased with increasing pH. The pastes obtained at pHs 4 and 7 showed marked instability by forming a mass of hard coarse gel with the first freeze-thaw cycle while the paste of pH 9.2 maintained its normal viscoelastic-gel texture even after the fourth freeze-thaw cycle. The properties of the ascorbic acid granules and tablets produced by wet granulation, using the pastes as binder showed pH-responsiveness, with the granule formed with the paste of pH 9.2 showing higher mechanical strength and lower disintegration time. This study thus shows the diversity in the physicochemical and binder properties of tigernut starch with changes in pH. [ABSTRACT FROM AUTHOR]

Purpose: To characterize some preformulation properties of aqueous stem bark extract of Bridelia ferruginea Benth (Euphorbiaceae) (BF). Methods: The stem bark was extracted by maceration in hot distilled water. Two batches of granules containing the extract were prepared by wet granulation using maize starch, polyvinylpyrrolidone (PVP), Avicel® PH-101, magnesium stearate, acacia and lactose as excipients. Some physicochemical and micromeritic properties of the powdered extract and granules were determined following standard procedures. Results: The pH of the aqueous BF extract was 5.4 ± 0.1 while the moisture content of the dry extract was 12.0 %. Total ash value of the extract was 7.91 ± 0.03. Particle size increased after granulation from 228 to 531 µm in the order: granules 1 > granules 2 > powder. The bulk and tapped densities decreased significantly (p < 0.05) from 0.40 ± 0.04 to 0.77 ± 0.09 and 0.49 ± 0.05 to 0.85 ± 0.09 g/ml, respectively in the order: granules 2 < granules 1 < powder. Similarly, the angle of repose increased after granulation from 24.0 ± 0.5 to 25.4 ± 0.9 o in the order: granules 2 < granules 1 < powder (p < 0.05). The flow rate and compressibility of the granules (2.45 ± 0.08 g/min and 0.17, respectively) improved significantly (p < 0.05) over those of the powdered BF extract (2.34 ± 0.05 g/min and 0.26, respectively). Conclusion: The results of this preformulation study indicates that the powdered extract of Bridelia ferruginea possesses properties that make it suitable for its formulation into standard solid dosage forms. [ABSTRACT FROM AUTHOR]

Context: Bridelia ferruginea Benth (Euphorbiaceae) is an indigenous medicinal plant in Nigeria. It is usually a gnarled shrub which sometimes reaches the size of a tree in suitable condition. Decoctions of parts of this plant have been employed in ethno medicine in many parts of Africa for treatment of many ailments including malaria fever. Objective: In vivo antiplasmodial activity of aqueous stem bark extract of BF was investigated against Plasmodium berghei-infected mice. Materials and methods: The aqueous stem bark extract of BF (100–400mg/kg) was administered orally to P. berghei-infected mice in both early and established models of antiplasmodial studies. Results: The extract exhibited significant (p<0.05) antiplasmodial activity in early and established infection tests with a considerable mean survival time comparable to that of chloroquine, 10mg/kg. The oral LD50 obtained was greater than 5000mg/kg in mice. Discussion and conclusions: The findings show that aqueous stem bark extract of Bridelia ferruginea possesses considerable antiplasmodial activity which can be developed in malaria therapy. [ABSTRACT FROM AUTHOR]

The aim of this work was to evaluate the hepatoprotective potential of fractions and phytosomal complexes of Telfairia occidentalis leaf extracts on ethanol-induced hepatotoxicity in rat models. Phytosomal complexes of ethanol extract fractions were prepared by the thin film hydration technique. Hepatoprotective activities were evaluated by biochemical assays and histopathological examination of liver sections. Intoxication of animals with pure ethanol significantly (p < 0.05) elevated their liver enzyme titers, whereas co-administration with various extracts and phytosomal complexes reversed the increases. Histopathological findings revealed liver tissue protective effects of the extracts with the phytosomal complexes exhibiting greater effects (p < 0.05). Significant differences at p ≤ 0.05 were observed in the liver indices of animals treated with co-administered ethanol and extract fractions or phytosomes complexes versus the positive control group. T. occidentalis leaf extract formulated as phytosomes, therefore, has good potential of enhancing the hepatoprotective activities of the extract. [ABSTRACT FROM AUTHOR]

Purpose: To study the release behaviour of ciprofloxacin hydrochloride tablet matrices prepared with different polymers in dissolution media of different pH. Methods: Different formulations of slow-release matrix tablets of ciprofloxacin hydrochloride were prepared with polymers, namely, ethyl cellulose (Etc), hydroxyethyl cellulose (Hec), hydroxypropyl methylcellulose (Hpc), and Eudragit® L-100 (Eud) using matrix embedding technique. The matrix tablets were characterized and studies of their dissolution profiles were studied in 0.1 N HCl (pH 1.2) and in simulated intestinal fluid (excluding enzymes) of pH 4.0, 6.0, and 7.4. Results: The tablets had the following characteristics: weight, 659.25 ± 7.96 to 661.65 ± 6.53 mg; hardness, 7.05 ± 0.21 to 9.60 ± 0.40 kgf; friability, 0.212 to 0.292 %; and drug content, 91.47 ± 0.53 to 112.50 ± 4.14 %. In batches prepared with ethyl cellulose, Eudragit L-100, and hydroxypropyl methylcellulose, drug release increased with a decrease in pH. However, matrix tablets prepared with hydroxyethyl cellulose displayed the highest drug release at pH 4.0 with Cmax of 108.75 % and T50% of 30.86 min; thereafter, drug release decreased with increase in pH. The pattern of drug release was Hec > Hpc > Eud > Etc in most media with more drug release in acidic than at alkaline pH. Conclusion: Release of ciprofloxacin from the formulated matrix tablets was pH-sensitive in vitro. This should be taken into consideration in designing sustained release oral form of ciprofloxacin. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the adsorptive interaction of Garcinia kola with spiramycin, since the kola is widely chewed as a tonic and spiramycin attains high concentrations in saliva. Methods: Spiramycin solutions of different concentration were added to a fixed mass of Garcinia kola (200 mg), activated charcoal or Veegum®. Shaking was carried out at room temperature after which the dispersion was filtered and the filtrate assayed for residual drug concentration. The process was repeated under different equilibrium conditions of pH and ionic strength. The adsorption data obtained for the three adsorbents were analyzed using Langmuir and Freundlich's plots. Results: At neutral pH, drug adsorprtion by Garcinia kola, activated charcoal and Veegum® were 67, 54 and 71%, respectively; differences in adsorption was not significant (p = 0.09). However, the other two adsorbents exhibited adverse adsorption characteristics in terms of negative adsorption capacity (- 5.78 mol.kg-1) and constant (-1141 mol-1L). For each of the adsorbents, pH and ionic strength affected the extent of adsorption, due to their effect on adsorbent surface charge. Correlation with Langmuir and Freundlich relationships were poor, the correlation coefficient for the latter being 0.97, 0.894 and 0.351 for Garcinia kola, Veegum® and activated charcoal, respectively. Conclusion: The study reveals that Garcinia kola significantly adsorbs spiramycin under alkaline conditions comparable to salivary pH, and therefore should not be taken concurrently with the drug in order to minimize reduction in drug levels. [ABSTRACT FROM AUTHOR]