High-performance thin layer chromatography to assess pharmaceutical product quality.

OBJECTIVE: To assess the sustainability, robustness and economic advantages of high-performance thin layer chromatography (HPTLC) for quality control of pharmaceutical products. METHOD: We compared three laboratories where three lots of cotrimoxazole tablets were assessed using different techniques for quantifying the active ingredient. RESULT: The average assay relative standard deviation for the three lots was 1.2 with a range of 0.65-2.0. CONCLUSION: High-performance thin layer chromatography assessments are yielding valid results suitable for assessing product quality. The local pharmaceutical manufacturer had evolved the capacity to produce very high quality products.

Prevalence of Urinary Tract Infections and Antibiogram of Bacteria Isolated From Children With Sickle Cell Disease in Tanzania.

Introduction Individuals with sickle cell disease (SCD) are particularly vulnerable to urinary tract infections (UTIs) due to immunological deficits and renal abnormalities associated with the disorder. These infections can exacerbate underlying health issues and lead to severe complications if not managed promptly and effectively. Due to the heightened risk and potential consequences of UTIs in this population, this study aimed to determine their prevalence and explore the resistance patterns of causative pathogens among children attending the SCD Clinic at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. Focusing on this demographic group, we sought to provide targeted insights to inform better clinical protocols and intervention strategies in regions heavily affected by SCD. Materials and methods This prospective cross-sectional study was conducted at the MNH, Dar es Salaam, Tanzania, with an enrollment over two months from 19th March to 21st May 2015. We diagnosed UTIs in children with SCD using dipstick and culture methods. Antibiotic susceptibility was assessed using the Kirby-Bauer disc diffusion method, evaluating resistance patterns to antibiotics such as ampicillin, cloxacillin, erythromycin, chloramphenicol, ceftriaxone, and trimethoprim-sulfamethoxazole. The diagnostic accuracy of the dipstick and culture methods was validated to ensure reliability in detecting UTIs. Statistical analysis was conducted using Statistical Product and Service Solutions (SPSS) software (Released 2019; IBM Corp., Armonk, New York, United States). Results Among the 250 children, 56 (22.4%) were UTI-positive according to the culture method and 62 (24.8%) were UTI-positive according to the dipstick test. Girls were more likely to be UTI-positive than boys (29.1% and 13.6%, respectively; p-value = 0.011). Escherichia coli was the most common uropathogen, followed by Klebsiella, Staphylococcus, Proteus, and Pseudomonas (44.2%, 26.9%, 21.2%, 3.8%, and 1.9%, respectively). All isolates were resistant to ampiclox. Resistance rates to ampicillin, erythromycin, cotrimoxazole, chloramphenicol, and ceftriaxone were 94.2%, 76.9%, 59.6%, 46.2%, and 21.2%, respectively. Conclusion This study indicated that dipsticks diagnosed more UTIs. The prevalence was higher in girls than in boys. Escherichia coli was the most commonly isolated antibiotic-resistant organism. High resistance levels were observed against the combination of ampicillin and cloxacillin. However, the isolates were less resistant to ceftriaxone. These results call for increased surveillance of resistant uropathogens in the pediatric population with SCD.

Development and validation of an improved reversed-phase liquid chromatographic method combined with pulsed electrochemical detection for the analysis of netilmicin.

Netilmicin is one of the aminoglycoside antibiotics that lacks a strong UV absorbing chromophore. However, the application of pulsed electrochemical detection has been used successfully for the direct analysis of aminoglycoside antibiotics. This study describes an improved LC method combined with pulsed electrochemical detection for the analysis of netilmicin. Using a Zorbax SB C-18 column (250 mm x 4.6 mm id, 5 microm), isocratic elution was carried out with a mobile phase containing sodium sulfate (20 g/L), sodium octanesulfonate (0.3 g/L), THF (20 mL/L), and 0.2 M phosphate buffer pH 3.0 (50.0 mL/L). The robustness of the method was examined by means of an experimental design. The method proved to be sensitive, repeatable, linear, and robust. The method has also been used to analyze some commercial netilmicin samples.

Assessment of Implementation of Antimicrobial Resistance Surveillance and Antimicrobial Stewardship Programs in Tanzanian Health Facilities a Year After Launch of the National Action Plan.

Introduction: Antimicrobial resistance (AMR) is a current global health threat and a challenge to the treatment of infectious diseases. The WHO advocates a strategy of antibiotic stewardship programs (ASP) in optimizing antimicrobial use in hospitals. This study aimed at assessing the existence of AMR surveillance and ASP implementation in health facilities in Tanzania in the year following the launch of the National Action Plan (NAP). Methodology: From December 2017 through July 2018, a descriptive cross-sectional study was conducted using a structured questionnaire administered online. A total of 199 health facilities in Tanzania mainland whose contacts was obtained from the Ministry of Health Community Development Gender Elderly and Children (MoHCDGEC) were reached by phone and thereafter, a survey was sent via text or e-mail to focal persons in the corresponding facilities. Results: Only 39 (32.5%) responses from contacted facilities were received and analyzed. Thirty (76.9%) of the facilities were government-owned. Of the 39 respondents surveyed, 13 (35.9%) declared to have implemented some sort of coordinated ASP to promote the rational use of antimicrobials at their facilities. The respondents reported the presence of guidelines for the implementation of ASP at variable proportions, whereas the presence of a committee for Infection Prevention and Control was reported by 27 (69.2%). Twenty-four (61.5%) had a Medical and Therapeutic Committee. Although all 39 (100%) respondents were aware of the presence of AMR in Tanzania, only 26 (66.7%) were aware of the presence of the Tanzanian NAP for AMR. Hospital antibiotic policy document was present in 6 (15.4%) facilities. Only 7 (17.9%) facilities conducted prescription auditing; 9 (23.1%) had a hospital formulary; 14 (35.9%) had standard hospital prescription. 9 (23.1%) had software for data storage about AMR. Only 7 (17.9%) facilities conducted microorganisms' susceptibility tests and kept the record of the microorganism susceptibility testing. Conclusion: Our study found the existence of AMR surveillance activities and ASP implementation in Tanzania, albeit at a low level. The implementation was inconsistent across the surveyed facilities. These data have identified areas of improvement in addressing AMR in Tanzania through the NAP.

Improved liquid chromatographic method with pulsed electrochemical detection for the analysis of gentamicin.

The official method for the determination of the composition and related substances of gentamicin prescribed by the European Pharmacopoeia (Ph. Eur.) is liquid chromatography combined with pulsed electrochemical detection (LC-PED). However, this method utilizes a polymer stationary phase which shows rather low efficiency towards the separation of the main gentamicin components. Moreover, the mobile phase contains a lot of non volatile salts: sodium sulphate and sodium octanesulphonate. Following a comparative study, the most performant LC-PED method has been evaluated and validated using a reversed phase C18 column (C18, 250 x 4.6mm ID, 110 A, 5 microm) kept at 35 degrees C with a mobile phase containing volatile ion pairing agents: trifluoroacetic acetic acid (TFA) and pentafluoropropionic acid (PFPA). In addition to the selectivity of the main gentamicin components and its related substances, the method is repeatable, linear and proves to be robust. It is also applicable to a wider number of C18 columns.

Comparison of liquid chromatographic methods with direct detection for the analysis of gentamicin.

Several liquid chromatographic (LC) methods have been described for the analysis of gentamicin. LC combined with pulsed electrochemical detection (LC-PED) or evaporative light scattering detection (LC-ELSD) was found to be the most suitable technique. A first method, previously developed by Adams et al. used a poly(styrene-divinyl benzene) stationary phase with a mobile phase containing sodium sulphate, sodium-1-octanesulphonate, tetrahydrofuran, 0.2M phosphate buffer (pH 3) and water. However, the polymer columns show low efficiency, which also leads to poor sensitivity. So, recently the use of newer conventional C18 columns was further investigated. Improved separation was obtained using a Supelcosil LC-18-DB column with an adapted mobile phase. Another method derived from a company method was checked by using a Gemini column and a mobile phase containing an aqueous solution of trifluoroacetic acid (TFA) and pentafluoropropionic acid (PFPA) adjusted to pH 2.6 with sodium hydroxide (NaOH). This method was transferred to ELSD by replacing the non-volatile NaOH with volatile ammonium hydroxide solution. A volatile method, which was originally developed for ELSD using an aqueous solution of 50mM TFA and gradient elution with methanol, was also combined with PED. In this study, these methods were compared with regard to their selectivity, sensitivity and ease of use.

The Quality of Selected Essential Medicines Sold in Accredited Drug Dispensing Outlets and Pharmacies in Tanzania.

INTRODUCTION: The purpose of this study was to investigate the quality of a select group of medicines sold in accredited drug dispensing outlets (ADDOs) and pharmacies in different regions of Tanzania as part of an in-depth cross-sectional assessment of community access to medicines and community use of medicines. METHODS: We collected 242 samples of amoxicillin trihydrate, artemether-lumefantrine (ALu), co-trimoxazole, ergometrine maleate, paracetamol, and quinine from selected ADDOs and pharmacies in Mbeya, Morogoro, Singida, and Tanga regions. The analysis included physical examination and testing with validated analytical techniques. Assays for eight of nine products were conducted using high-performance thin-layer chromatography (HPTLC). For ALu tablets, we used a two-tiered approach, where tier 1 was a semi-quantitative Global Pharma Health Fund-Minilab® method and tier 2 was high-performance liquid chromatography (HPLC) as described in The International Pharmacopoeia's monograph for artemether-lumefantrine. RESULTS AND DISCUSSION: The physical examination of samples revealed no defects in the solid and oral liquid dosage forms, but unusual discoloration in an injectable solution, ergometrine maleate. For ALu, the results showed that of 38 samples, 31 (81.6%) passed tier 1 testing and 7 (18.4%) gave inconclusive drug content results. The inconclusive ALu samples were submitted for tier 2 testing and all met the quality standards. The pass rate using the HPTLC and TLC/HPLC assays was 93.8%; the failures were the ergometrine maleate samples purchased from both ADDOs and pharmacies. The disintegration testing of the solid dosage forms was conducted in accordance with US Pharmacopeia monographs. Only two samples of paracetamol, 1.2% of the solid dosage forms, failed to comply to standards. The study revealed a high overall rate of 92.6% of samples that met the quality standards. Although the overall failure rate was 7.4%, it is important to note that this was largely limited to one product and likely due to poor distribution and storage rather than poor manufacturing practices. CONCLUSIONS: Over 90% of the medicines sold in ADDOs and pharmacies met quality standards. Policy makers need to reconsider ergometrine maleate's place on the list of medicines that ADDOs are allowed to dispense, by either substituting a more temperature-stable therapeutically equivalent product or requiring those sites to have refrigerators, which is not a feasible option for rural Tanzania.

Challenges facing effective implementation of co-trimoxazole prophylaxis in children born to HIV-infected mothers in the public health facilities.

BACKGROUND: If children born to HIV-infected mothers are not identified early, approximately 30% of them will die within the first year of life due to opportunistic infections. In order to prevent morbidity and mortality due to opportunistic infections in children, the World Health Organization recommends the use of prophylaxis using co-trimoxazole. However, the challenges affecting effective implementation of this policy in Tanzania have not been documented. AIM: In this study, we assessed the challenges facing the provision of co-trimoxazole prophylaxis among children born to HIV-infected mothers in the public hospitals of Dar es Salaam, Tanzania. METHODOLOGY: Four hundred and ninety-eight infants' PMTCT (Prevention of Mother-to-Child Transmission of HIV) register books for the past 2 years were reviewed to obtain information regarding the provision of co-trimoxazole prophylaxis. One hundred and twenty-six health care workers were interviewed to identify success stories and challenges in the provision of co-trimoxazole prophylaxis in children. In addition, 321 parents and guardians of children born to HIV-infected mothers were interviewed in the health facilities. RESULTS: Approximately 80% of children were initiated with co-trimoxazole prophylaxis within 2 months after birth. Two hundred and ninety-one (58.4%) children started using co-trimoxazole within 4 weeks after birth. Majority (n=458, 91.8%) of the children were prescribed 120 mg of co-trimoxazole per day, whereas 39 (7.8%) received 240 mg per day. Only a small proportion (n=1, 0.2%) of children received 480 mg/day. Dose determination was based on the child's age rather than body weight. Parents and guardians reported that 42 (13.1%) children had missed one or more doses of co-trimoxazole during the course of prophylaxis. The majority of health care workers (89.7%) reported that co-trimoxazole is very effective for the prevention of opportunistic infections among children, but frequent shortage of co-trimoxazole in the health facilities was the main challenge. CONCLUSION: Most children who were initiated with co-trimoxazole prophylaxis did not experience significant opportunistic infections, and the drug was well tolerated. The major barrier for co-trimoxazole prophylaxis was due to frequent out-of-stocks of pediatric co-trimoxazole formulations in the health facilities. Dose determination was based on the age rather than the weight of children, thus creating potential for under- or over-dosing of children.

Improved reversed phase liquid chromatographic method with pulsed electrochemical detection for tobramycin in bulk and pharmaceutical formulation.

Tobramycin is one of the aminoglycoside antibiotics that lack a UV absorbing chromophore. However, the application of pulsed electrochemical detection (PED) has been used successfully for the analysis of this and similar antibiotics. This work describes an improved liquid chromatographic (LC) method combined with PED, which is able to separate much more impurities than before. Using a Discovery C-18 RP column (250 mm×4.6 mm i.d., 5 µm), isocratic elution was carried out with a mobile phase, containing sodium sulfate (35 g/L), sodium octanesulphonic acid (1 g/L), tetrahydrofuran (14 mL/L) and 0.2 M phosphate buffer pH 3.0 (50 mL/L). Using these experimental conditions, the limit of quantification (LOQ, S/N=10) was 5 ng. The linearity was examined in the range LOQ-60 µg/mL and the coefficient of determination was 0.998. The method also proved to be repeatable and the recovery was close to 100%. The influence of the different chromatographic parameters on the separation was investigated by means of an experimental design. The proposed method is useful in quality control of tobramycin drug substances and drug products.

Improved liquid chromatographic method with pulsed electrochemical detection for the analysis of kanamycin.

This work describes the separation of the main component kanamycin A from its related substances using an improved liquid chromatographic method with pulsed electrochemical detection (LC-PED). Two methods, one using volatile ion pairing agents and the other using non-volatile ones were developed. Using volatile additives, the total run time was rather long with no possibility of developing gradient elution. The non-volatile method was found to be more performant and hence was selected for further quantitative work. This method employed gradient elution in order to reduce the analysis time and to improve the sensitivity of the late eluting peaks. Mobile phase A consisted of sodium sulphate (5.0g/l), sodium octanesulphonate (0.5g/l) and 0.2M phosphate buffer pH 3.0 (50.0ml/l). Mobile phase B was the same as A except for the amount of sodium sulphate which was increased to 15g/l. Using a Platinum EPS column (150mmx4.6mm ID, 3microm) kept at 45 degrees C, 22 components could be separated within 45min indicating that this method is much more selective than other already published ones. Robustness of the method was examined by means of an experimental design. The limit of detection and limit of quantitation were found to be 1.7 and 5ng, respectively. The method was found to be linear in the range LOQ-600ng injected with a coefficient of determination equal to 0.999.

Development and validation of an improved liquid chromatographic method for the analysis of dirithromycin.

The official method for the determination of dirithromycin and related substances in the European Pharmacopoeia (Ph. Eur.) and in the United States Pharmacopeia (USP) is an isocratic liquid chromatographic (LC) method using an ODS column. With this method, the separation of the main component dirithromycin from its epimer is not complete. Moreover, this method suffers sometimes from drift of the baseline and from subsequent quantitation problems. The required resolution is not easy to obtain. Using an adapted method derived from the one prescribed in the pharmacopoeias, the selectivity of a set of more than 40 reversed-phase columns towards dirithromycin components was investigated. The selection of the most suitable column was achieved by the chromatographic response function (CRF) approach. Several changes were introduced to the method in order to improve the separation and to overcome the baseline drift problem. The resulting method uses a Zorbax Extend column maintained at 30 degrees C and a mobile phase containing acetonitrile, methanol, 2-propanol, water and a phosphate buffer at pH 7.5. The method allows a good separation of dirithromycin components, which is much better than that obtained with the existing methods. Several impurities of unknown identity are also separated. The method shows good repeatability, linearity and sensitivity, and it is robust. In addition, it proved to be applicable to a wide number of C18 reversed-phase columns.