ABSTRACT
Aims: This study was undertaken to compare the quality and efficacy of six brands of antibacterial discs that are commercially available in Nigeria. Methodology: The brands evaluated include two foreign brands (Oxoid and Abtek) and four local brands (Optudisc, Polydisc, Maxidisc and Jirehdisk). The brands were analyzed by antibiotic susceptibility testing (AST) using laboratory isolates of Staphylococcus aureus and Escherichia coli to measure the antimicrobial performances of the brands; and UV-Vis spectrophotometry to measure the absorbances of antibiotics extracted from antibiotic discs of the various brands. Results: All of the brands of antibacterial discs of under study exhibited variations in their antimicrobial performances and UV-absorbances. This was observed where some of the discs with lower stated potencies produced inhibition zones and absorbances far greater than similar discs from other brands with higher stated potencies. Also, discs of the same stated potencies showed variable results in both the antibiotic susceptibility testing (AST) and UV-Vis spectrophotometric analyses. Coefficients of variation greater than 5%, which indicates high disc-to-disc variation and unsatisfactory reproducibility, were recorded highest among the local brands during the AST. All the brands with multidisc panels, except the Abtek and Polydisc brands, produced some zones of inhibition that are unreadable. Of all the zones of inhibition that were unreadable, Optudisc brand recorded the highest rate (36·7%), while 6·7% of discs of Jirehdisk brand and 6·7% of discs of Maxidisc brand produced inhibition zones that were unreadable. Conclusion: All brands of susceptibility discs evaluated in this study except the Oxoid and Abtek brands manifested poor quality and performed below expected standard, though one of the local brands (Polydisc) performed closest to the foreign brands. With further improvement in quality, these brands may be recommended for use in Nigeria.
ABSTRACT
Aims: This study was designed to verify the immunogenicity (potency) and the safety of tetanus toxoid vaccines marketed in three large open drug markets in South-Eastern Nigeria. Methodology: Tests for Sterility, formaldehyde concentrations, specific toxicity, endotoxin, and immunogenicity (potency) were conducted on three different brands of tetanus toxoids (Brand α - from Ariaria Drug Market, Aba-Abia State; Brand β - from Ogbete Drug Market, Enugu State; and Brand γ - from Bridge-Head Drug Market, Onitsha-Anambra State). Results: All vaccine brands studied passed the sterility testing, but did not comply with the 2011 BP specifications on free formaldehyde concentration, which stipulates that the free formaldehyde concentration should not exceed 0.02%. The three vaccine brands did not show specific, abnormal, or general toxicity, but contained different amounts of endotoxins. The result of the potency testing showed that the three brands were immunogenic and elicited specific antibodies against tetanus toxin; but brand γ was the most immunogenic since it elicited the highest titers of total IgG, IgG1, and IgG2a followed by brand α, and then brand β. Conclusion: Generally, the quality control tests carried out on these three commercial brands of tetanus toxoids marketed in Nigeria showed that they do not comply with all the pharmacopeial standards on quality and safety required for vaccines of this nature. Therefore, we conclude that some of the tetanus toxoids marketed in open drug markets in Nigeria are substandard and may be responsible for the failures of these vaccines used for immunization in the country.
ABSTRACT
Aim: This study investigates the wound healing activity of ethanol leaf extract of Erythrina senegalensis using excision wound model on albino rats. Methodology: Several herbal extract formulations were prepared with Petroleum Jelly ointment base. Cicatrin® powder (neomycin-bacitracin) was used as the positive control. The various ointment formulations were applied topically on the wounds daily for 21 days. Daily wound contraction and epithelialisation times were recorded for each group. The antibacterial activity of the extract was also evaluated against some bacteria species implicated in wound infections. The following test organisms were used: Staphylococcus aureus, Pseudomonas aeruginosa, klebsiella pneumoniae and Escherichia coli. Results: The Phytochemical analysis revealed that alkaloids were abundant in the extract. The herbal ointment at various concentrations showed significant (P<.05) increase in percentage wound contraction on day 9 – 21 compared with the control group that received only the ointment base. The contraction produced by 40% w/w of the extract was similar to that of Cicatrin® powder on day 6 – 21. The results also revealed significant (P<.05) reduction in epithelialisation time exhibited by the extract treated animals compared to those of the control group. The result of antimicrobial studies showed that the extract inhibited the test organisms at concentrations ranging from 200 to 12.5 mg/mL. The Minimum Inhibitory Concentrations (MICs) of the extract on the test isolates was recorded at 25mg/mL for both S. aureus and E. coli and 6.25mg/ml for K. pneumoniae. P. aeruginosa showed no susceptibility to both the extract and the control drug at the concentrations evaluated. Conclusion: The marked reduction of wound size and epithelialisation time by the extract is an indication of its wound healing potentials. Also, the antibacterial activity of this plant against bacterial species implicated in wound infections may contribute to the enhanced wound healing activity.