Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infec...Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Half Maximal Inhibitory Concentrations (IC<sub>50</sub>) were obtained using the broth dilution method. The IC<sub>50’s</sub> of the drugs which were active against L. donovani were used as reference values to prepare drug combinations for the modified microdilution checkerboard method. Results: Five (5) out of the fifty-six (56) drugs used showed activity (inhibition of cell growth) against L. donovani cells. They include Quinine sulphate (IC<sub>50</sub> = 0.089 μg/ml), gentamicin (IC<sub>50</sub> = 8.1 μg/ml), amodiaquine (IC<sub>50</sub> = 138 μg/ml) and the two standard drugs: Amphotericin B (IC<sub>50</sub> = 6.3 μg/ml) and Pentamidine (IC<sub>50</sub> = 25 μg/ml). The remaining fifty-one (51) drugs did not show any inhibition within the range of concentrations used (1.25 - 160 μg/ml). The drug combinations of Pentamidine/Amodiaquine, Pentamidine/ Quinine sulphate, Pentamidine/Gentamicin, Amphotericin B/Quinine Sulphate, Amphotericin B/ Gentamicin, Amodiaquine/Quinine sulphate and Amodiaquine/Gentamicin showed synergistic effects against L. donovani whereas the Amphotericin B/Amodiaquine combination was antagonistic. Notable in the results obtained was the high effectiveness of quinine sulphate in inhibiting the growth of L. donovani. Quinine sulphate, though not indicated for leishmania treatment, was more effective than the two standard drugs and has a potential of playing a significant role in the treatment of leishmaniasis. Conclusion: This study has revealed five (5) anti-infective agents that by themselves or in combinations show activity against L. donovani. Some of the drug combinations which showed synergism should further be investigated. These results have to be confirmed by in vivo studies to define their roles in leishmaniasis treatment.展开更多
Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone or in combination against Mycobacterium smegmatis. Method: A convenient stratified sampling method was used to obtain selected anti-in...Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone or in combination against Mycobacterium smegmatis. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Minimum Inhibitory Concentrations (MIC) were obtained using the agar-well plate diffusion technique. Fractional Inhibitory Concentration Indices (FICI) were calculated for drug combinations using their MIC as obtained from the broth dilution method. Results: Of the thirty (30) anti-infective agents analyzed, ten (10) had MIC equivalent to or better than rifampicin (reference TB drug). Seven (7) drugs had MIC higher than rifampicin, while twelve (12) showed no growth inhibition of M. smegmatis. Analysis of the effect of drug combinations on M. smegmatis indicated that four (4) combinations, including rifampicin/ethambutol showed synergism. One (1) was additive, two (2) were indifferent and one (1) combination showed antagonism. Conclusion: Notable in the results obtained was the high effectiveness of the carbapenems in inhibiting the growth of M. smegmatis. Carbapenems, though not indicated for TB treatment, has a potential of playing a significant role in the treatment of tuberculosis. Also the drug combinations which showed synergism, especially those that involved the macrolide antibiotics, should further be investigated. These results have to be confirmed by in vivo clinical studies to define their roles in tuberculosis treatment.展开更多
Aim: To assess the quality and in vitro efficacy of five brands of amoxicillin/clavulanic acid tablet, suspension and injectable preparations selected from pharmacies in the Central Region of Ghana. Method: Using a St...Aim: To assess the quality and in vitro efficacy of five brands of amoxicillin/clavulanic acid tablet, suspension and injectable preparations selected from pharmacies in the Central Region of Ghana. Method: Using a Stratified Representation Sampling method, forty preparations (tablets, suspensions and injectable powders) containing amoxicillin and clavulanic acid were sampled from nine different locations within the Central Region of Ghana. To determine drug quality, several procedures, namely, content assay, disintegration and dissolution testing were employed. In vitro drug efficacy was determined by comparing the Minimum Inhibitory Concentrations (MIC’s) obtained with published values. Results: All tablets passed the disintegration test, with disintegration time ranging between six (6) and fifteen (15) minutes. Analyses of all the tablets for drug content showed 100% failure (14 out of 14) for amoxicillin and 14% failure (2 out of 14) for clavulanic acid. Injectable formulations showed similar results. All four (4) samples analyzed for content failed the amoxicillin content assay (0 out of 4) but all passed clavulanic acid assay (4 out of 4). For tablet dissolution tests, there was a 93% (13 out of 14) pass rate for both amoxicillin and clavulanic acid. Content analysis of all suspension formulations involved twenty-two (22) samples from five (5) brands. Only 41% (9 out of 22) passed for both amoxicillin and clavulanic acid. All the other samples failed for either amoxicillin, clavulanic acid or both. Results obtained from drug quality tests were confirmed by in vitro efficacy tests against selected microorganisms. Conclusion: The samples were therefore not of good quality, since content assay is the most crucial test. It is hypothesized that this is due to poor storage conditions, and recommendations, such as air conditioning and more structured procedures along the supply chain, are put forward to counteract this.展开更多
Sepsis is a host’s response to an intravascular infection;however, in most patients the disease recurs after a seemingly effective treatment. The reappearance of bacteria in the systemic circulation has been attribut...Sepsis is a host’s response to an intravascular infection;however, in most patients the disease recurs after a seemingly effective treatment. The reappearance of bacteria in the systemic circulation has been attributed to their ability to enter and hide within host endothelial cells. This study shows that internalized S. aureus is released into circulation by a possible mechanism of exocytosis through actin polymerization. Bacterial cell wall components (permeation enhancers) were significantly more effective in altering endothelial cell monolayer integrity than controls. Vancomycin has been determined to be effective in the treatment of S. aureus infections;however, the microencapsulated formulation of vancomycin was significantly more effective in reducing plasma and intra-tissue S. aureus than the conventional solution formulation. Microencapsulation of vancomycin, using albumin as a matrix, did not alter the bioactivity of the drug.展开更多
文摘Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Half Maximal Inhibitory Concentrations (IC<sub>50</sub>) were obtained using the broth dilution method. The IC<sub>50’s</sub> of the drugs which were active against L. donovani were used as reference values to prepare drug combinations for the modified microdilution checkerboard method. Results: Five (5) out of the fifty-six (56) drugs used showed activity (inhibition of cell growth) against L. donovani cells. They include Quinine sulphate (IC<sub>50</sub> = 0.089 μg/ml), gentamicin (IC<sub>50</sub> = 8.1 μg/ml), amodiaquine (IC<sub>50</sub> = 138 μg/ml) and the two standard drugs: Amphotericin B (IC<sub>50</sub> = 6.3 μg/ml) and Pentamidine (IC<sub>50</sub> = 25 μg/ml). The remaining fifty-one (51) drugs did not show any inhibition within the range of concentrations used (1.25 - 160 μg/ml). The drug combinations of Pentamidine/Amodiaquine, Pentamidine/ Quinine sulphate, Pentamidine/Gentamicin, Amphotericin B/Quinine Sulphate, Amphotericin B/ Gentamicin, Amodiaquine/Quinine sulphate and Amodiaquine/Gentamicin showed synergistic effects against L. donovani whereas the Amphotericin B/Amodiaquine combination was antagonistic. Notable in the results obtained was the high effectiveness of quinine sulphate in inhibiting the growth of L. donovani. Quinine sulphate, though not indicated for leishmania treatment, was more effective than the two standard drugs and has a potential of playing a significant role in the treatment of leishmaniasis. Conclusion: This study has revealed five (5) anti-infective agents that by themselves or in combinations show activity against L. donovani. Some of the drug combinations which showed synergism should further be investigated. These results have to be confirmed by in vivo studies to define their roles in leishmaniasis treatment.
文摘Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone or in combination against Mycobacterium smegmatis. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Minimum Inhibitory Concentrations (MIC) were obtained using the agar-well plate diffusion technique. Fractional Inhibitory Concentration Indices (FICI) were calculated for drug combinations using their MIC as obtained from the broth dilution method. Results: Of the thirty (30) anti-infective agents analyzed, ten (10) had MIC equivalent to or better than rifampicin (reference TB drug). Seven (7) drugs had MIC higher than rifampicin, while twelve (12) showed no growth inhibition of M. smegmatis. Analysis of the effect of drug combinations on M. smegmatis indicated that four (4) combinations, including rifampicin/ethambutol showed synergism. One (1) was additive, two (2) were indifferent and one (1) combination showed antagonism. Conclusion: Notable in the results obtained was the high effectiveness of the carbapenems in inhibiting the growth of M. smegmatis. Carbapenems, though not indicated for TB treatment, has a potential of playing a significant role in the treatment of tuberculosis. Also the drug combinations which showed synergism, especially those that involved the macrolide antibiotics, should further be investigated. These results have to be confirmed by in vivo clinical studies to define their roles in tuberculosis treatment.
文摘Aim: To assess the quality and in vitro efficacy of five brands of amoxicillin/clavulanic acid tablet, suspension and injectable preparations selected from pharmacies in the Central Region of Ghana. Method: Using a Stratified Representation Sampling method, forty preparations (tablets, suspensions and injectable powders) containing amoxicillin and clavulanic acid were sampled from nine different locations within the Central Region of Ghana. To determine drug quality, several procedures, namely, content assay, disintegration and dissolution testing were employed. In vitro drug efficacy was determined by comparing the Minimum Inhibitory Concentrations (MIC’s) obtained with published values. Results: All tablets passed the disintegration test, with disintegration time ranging between six (6) and fifteen (15) minutes. Analyses of all the tablets for drug content showed 100% failure (14 out of 14) for amoxicillin and 14% failure (2 out of 14) for clavulanic acid. Injectable formulations showed similar results. All four (4) samples analyzed for content failed the amoxicillin content assay (0 out of 4) but all passed clavulanic acid assay (4 out of 4). For tablet dissolution tests, there was a 93% (13 out of 14) pass rate for both amoxicillin and clavulanic acid. Content analysis of all suspension formulations involved twenty-two (22) samples from five (5) brands. Only 41% (9 out of 22) passed for both amoxicillin and clavulanic acid. All the other samples failed for either amoxicillin, clavulanic acid or both. Results obtained from drug quality tests were confirmed by in vitro efficacy tests against selected microorganisms. Conclusion: The samples were therefore not of good quality, since content assay is the most crucial test. It is hypothesized that this is due to poor storage conditions, and recommendations, such as air conditioning and more structured procedures along the supply chain, are put forward to counteract this.
文摘Sepsis is a host’s response to an intravascular infection;however, in most patients the disease recurs after a seemingly effective treatment. The reappearance of bacteria in the systemic circulation has been attributed to their ability to enter and hide within host endothelial cells. This study shows that internalized S. aureus is released into circulation by a possible mechanism of exocytosis through actin polymerization. Bacterial cell wall components (permeation enhancers) were significantly more effective in altering endothelial cell monolayer integrity than controls. Vancomycin has been determined to be effective in the treatment of S. aureus infections;however, the microencapsulated formulation of vancomycin was significantly more effective in reducing plasma and intra-tissue S. aureus than the conventional solution formulation. Microencapsulation of vancomycin, using albumin as a matrix, did not alter the bioactivity of the drug.
