Effects of the diluent type on compressional characteristics of the mixed stem bark extract of Anogeissus leiocarpus and Prosopis africana tablet formulation.

The hot water extract of a mixture of stem barks of Anogeissus leiocarpus and Prosopis africana was formulated into tablets using the wet granulation method of massing and screening. The Heckel equation was used to study the compaction characteristics of the extract formulated with lactose (water-soluble) or magnesium carbonate (water-insoluble) as diluents. Granules prepared using magnesium carbonate were found to exhibit two stages of deformation - an initial fragmentation followed by plastic flow while those formulated with lactose consolidated mainly by plastic deformation. Compressibility profiles of the formulations were affected by the diluent type. Tensile strength of granules formulated with magnesium carbonate was found to increase as the compression pressure increased from 56.6 to 113.2 MN m(-2) while the tensile strength of tablets formulated with lactose had its maximum at a compression force of 84.9 MN m(-2).

Double-blind, placebo-controlled, randomised cross-over clinical trial of NIPRISAN in patients with Sickle Cell Disorder.

The study was undertaken to determine the safety and efficacy of NIPRISAN, a phytomedicine, developed for the management of patients with Sickle Cell Disorder (SCD). The study design is a placebo-controlled double blind cross-over trial. Eighty-two (82) patients with SCD were recruited and randomised into two groups. An initial 4 month pre-trial study was undertaken to determine the similarity of the groups. The main study was conducted over a twelve-month period with crossover at six months. Safety of the drug was assessed clinically and biochemically. NIPRISAN significantly (P < 0.01) reduced the frequency of SCD crisis associated with severe pains. Acute toxicity to the liver assessed by the activities of liver enzymes, indicate that NIPRISAN is safe. Renal function assessed by the serum levels of creatinine and blood urea nitrogen remained normal. Both the clinical and laboratory results of the present phase IIB (pivot) clinical study suggest that NIPRISAN is a safe and efficacious phytomedicine for the management of patients with Sickle Cell Disorder.

Consequences of inadvertent microbial contamination of dextrose solutions.

Most intravenous infusion fluids and non-sterile liquid products contain dextrose which serves as a sweetener or an energy source for critically ill or traumatized patients. Hence dextrose was critically examined for stability in the presence of some micro-organism which are commonly known to contaminated i.v. infusion fluids. In the presence of these test organisms, the dextrose component of these solutions was found to be remarkably degraded with average rates of 0.065-3.153% per hour depending on the type of organism. Micro-organisms such as Ps. aeruginosa and E. coli gave low rates of degradation of 0.065-0.88% per hour while the values of 0.770-3.153% per hour were obtained for K. pneumonia; B-lac+ Staph. aureus and B. subtilis. The degradation of dextrose by C. albicans however, increased with dextrose concentration with average rate of 1.147-1.21% per hour. The degradations were gradually accompanied by increases in total acidity and decreases in pH of the dextrose solutions. The variation in the rates of degradation of dextrose by the test organisms is attributable to their survival rates in dextrose solutions and it is of great significance especially at the low inoculum size of 100 cells/ml. The results thus obtained necessitate the maintenance of a high level of aseptic procedures to prevent inadvertent contamination of i.v. fluids and other glucose containing solutions during clinical and other use conditions.

Kinetics of bacterial growth in simple intravenous solutions and admixtures.

The growth of bacteria in intravenous solutions and admixtures has been studied under stationary conditions of incubation. All the solutions were inoculated with 100 organisms/ml, incubated at room temperature (27 degrees C) or (37 degrees C), with samples withdrawn at specified time intervals, and plated in quadruplicates. The simple intravenous (i.v.) solutions did not support significant growth (P greater than 0.05) of any of the micro-organisms. Growth in i.v. solutions containing 1% blood was very significant (P greater than 0.05), as demonstrated by the high apparent growth rate constants (K). The ratio of K for beta-lactamase producing bacteria (beta-lac+) over that for non-beta-lactamase producing bacteria (beta-lac-) was significant (P less than 0.05) at 37 degrees C compared to that at 27 degrees C. The higher K values for B. cereus in benzylpenicillin and cefuroxime solutions, respectively, compared to those in antibiotic-free solutions, may be attributable to hydrolysis of the drugs, while the low K values for B. subtilis in the same solutions may be attributed to the inhibitory effects of the drugs. In conclusion, minute quantities of blood in i.v. solution tend to cause bacteria to multiply rapidly. The presence of beta-lactamase producing species might, in addition, hydrolyse susceptible beta-lactam antibiotics which are common additives to i.v. fluids.

Influence of drying methods on granule and tablet properties.

Three methods of drying pharmaceutical granules have been investigated using tray, fluidized-bed and intra-red dryers. A comparative study of the dryers' thermal efficiency and drying time and their effects on granule and tablet properties is presented. Fluidized-bed and intra-red dryers were found to have a 2- to 5-fold advantage in thermal efficiency over tray dryers in granule drying with the fluidized bed dryer being the most efficient. The granules dried by these two dryers also produced of better physical properties (quality) than those of tray dryer, in the formulation of tablets of both soluble and insoluble organic medicinal substances.

Influence of surfactant-treated starch on the disintegration and dissolution of sulphadiazine tablets.

The effects of treating cassava starch with sodium lauryl sulphate and Polysorbate 80 and the method of incorporating the treated and plain starch as disintegrant on the physical properties of sulphadiazine tablets were investigated. Disintegration and dissolution rates were faster with starch in which surfactant was incorporated in dry state than with starch treated with solution of surfactant. A direct correlation was observed between the Hardness-Friability Index and T90 values. Polysorbate 80-treated starch exhibited a better dissolution profile than SLS-treated starch.

Temperature effects on the binding efficiency of starch pastes.

The effect of temperature on the binding efficiency of yam starch and cassava starch pastes has been investigated. Starch pastes prepared at different temperatures were used to granulate lactose powder and the resulting granules and tablet properties were evaluated. Increased average granule size and decreased percentage fines were observed as the pasting temperature was increased upto a certain level and then there was a decrease in average size and increase in amount of fines as the pasting temperature was further increased. Granules prepared with yam starch pastes exhibited relatively lower amount of fines and larger average granule size. The corresponding tablets also showed higher crushing strength values and were less friable. Although the disintegration time of tablets was found to increase with the temperature of pasting of both the starches, no relationship between the pasting temperature and the crushing strength of tablets was observed. The release of amylose/amylopectin from starch grains, the amylopectin chain length and the amount of free molecular components as the pasting temperature increased are believed to be the factors contributing to the increased binding efficiency of the starch pastes.