In vitro evaluation of the application of an optimized xylanase cocktail for improved monogastric feed digestibility.

Xylanases from glycoside hydrolase (GH) families 10 and 11 are common feed additives for broiler chicken diets due to their catalytic activity on the nonstarch polysaccharide xylan. This study investigated the potential of an optimized binary GH10 and GH11 xylanase cocktail to mitigate the antinutritional effects of xylan on the digestibility of locally sourced chicken feed. Immunofluorescence visualization of the activity of the xylanase cocktail on xylan in the yellow corn of the feed showed a substantial collapse in the morphology of cell walls. Secondly, the reduction in the viscosity of the digesta of the feed by the cocktail showed an effective degradation of the soluble fraction of xylan. Analysis of the xylan degradation products from broiler feeds by the xylanase cocktail showed that xylotriose and xylopentaose were the major xylooligosaccharides (XOS) produced. In vitro evaluation of the prebiotic potential of these XOS showed that they improved the growth of the beneficial bacteria Streptococcus thermophilus and Lactobacillus bulgaricus. The antibacterial activity of broths from XOS-supplemented probiotic cultures showed a suppressive effect on the growth of the extraintestinal infectious bacterium Klebsiella pneumoniae. Supplementing the xylanase cocktail in cereal animal feeds attenuated xylan's antinutritional effects by reducing digesta viscosity and releasing entrapped nutrients. Furthermore, the production of prebiotic XOS promoted the growth of beneficial bacteria while inhibiting the growth of pathogens. Based on these effects of the xylanase cocktail on the feed, improved growth performance and better feed conversion can potentially be achieved during poultry rearing.

Enhanced production of a recombinant xylanase (XT6): optimization of production and purification, and scaled-up batch fermentation in a stirred tank bioreactor.

The endoxylanase XT6 produced by Geobacillus stearothermophilus is a desirable candidate for industrial applications. In this study, the gene encoding XT6 was cloned using the pET-28a expression vector and expressed in Escherichia coli BL21 (DE3) cells. Recombinant XT6 production was improved by optimizing cell lysis (sonication, chemical, and enzymatic lysis) and expression conditions. Sonication in a 0.05 M sodium phosphate (pH 6.0) buffer resulted in the highest xylanase activity (16.48 U/ml). Screening and optimization of induction conditions using the Plackett-Burman Design and Box-Behnken Design (BBD) approaches revealed that cell density pre-induction (OD600 nm), post-induction incubation time, and IPTG concentration significantly (p < 0.05) influenced the expression levels of XT6 (16.48 U/ml to 40.06 U/ml) representing a 3.60-fold increase. BBD resulted in a further 8.74-fold increase in activity to 144.02 U/ml. Batch fermentation in a 5-l stirred tank bioreactor at 1 vvm aeration boosted recombinant xylanase production levels to 165 U/ml suggesting that heterologous expression of the XT6 enzyme is suitable for scaled-up production. The pure enzyme with a molecular weight of 43 kDa and a 15.69-fold increase in purity was obtained using affinity chromatography and a cobalt column. Future studies will include application of the purified recombinant xylanase to animal feed.

Storage conditions, microbial quality, and transport costs of drinking water from alternative sources in a South African municipality.

Makana Local Municipality is located in the Eastern Cape Province of South Africa. The area is water-scarce and has been undergoing aridification in recent years, ie, there has been a 7-year long drought. At the same time, there has been a breakdown in provision of municipal services, such as drinking water, to the population since at least 2008. Mi-crobial water quality has been a result of this, and monitoring has been a challenge. Given the drought and the prob-lems with drinking water delivery, it was necessary to conduct this study to investigate the microbial quality of alterna-tive water resources that the Makana population can use during the municipal water outage. The microbial water quality of alternative sources of drinking water in the Makana Local Municipality was examined using the H2S test kit and enumeration of the fecal coliforms. Storage of the collected water was examined for potential factors influencing the microbial water quality of the alternative sources of drinking water. The costs of the water provision from the most suitable alternative sources of potable water were calculated. There was a general correlation between the H2S test kit results and the fecal coliform concentrations, with the latter values ranging from <0 to 23 ± 7 colony-forming units/100 mL. The bottled water from two retail outlets was provided the best alternative source of potable/drinking water, which is microbially safe, for the Makana population. If the consumption of the drinking water from an alternative source takes place within 24 hours of collection, then the Fairview spring could also be used as a source of drinking water for Maka-na residents. The total cost per 1 L of drinking water from alternative sources was estimated to be from 1.51 to 5.81 ZAR. Therefore, the maximum cost of daily provision of drinking water from alternative sources would account for a maximum of 0.88 percent of the monthly household expenditure in the middle-to-high-income household. However, the daily costs of such provision of drinking water would account for a maximum of 8.11 percent of the monthly household expenditure in the low-income household. Provision of the drinking water from the alternative sources would have a minor impact of the monthly ex-penditure in the middle-to-high-income households. However, it is likely that the low-income households would not be able to sustain their water supply from alternative sources for longer than 24 hours, during a municipal outage in the drinking water supply.

Evaluation of Risk-Based Approaches to the Registration of Medicines: Current Status Among African Regulatory Authorities.

BACKGROUND: Despite the worldwide need for increased access to safe and effective medicines, there is a lack of innovative medicines in many low- to middle-income countries. On the African continent, this is partly due to capacity limitations of National Regulatory Authorities (NRAs). One important approach to address this issue is work sharing and regulatory reliance. Therefore, the aim of this study of regulatory authorities on the African continent was to identify which risk-based approaches are being used as well as their foreseen role in the future. METHODS: The study employed a questionnaire to identify which risk-based models are used for the regulatory approval of medicines and to determine which frameworks are in place to enable a risk-based approach, as well as to provide insight into the future direction for risk-based models. The questionnaire was sent electronically to 26 NRAs in the African Continent. RESULTS: Twenty-one authorities (80%) completed the questionnaire. Work sharing was the most commonly used model, followed closely by unilaterial reliance, information sharing, and collaborative review. These methods were perceived to be an effective and efficient use of resources, enabling faster medicine availability for patients. The unilateral reliance approach by the authorities included abridged (85%), verification (70%) and recognition (50%) models for a range of products. However, challenges included a lack of guidelines to undertake a reliance review together with resource constraints, while access to assessment reports was the most common barrier to using a unilateral reliance model. CONCLUSIONS: Many authorities in Africa have adopted a risk-based approach to medicines registration and created work sharing, unilateral reliance pathways and regionalisation models to facilitate the availability of medicines. The authorities believe that in future, assessment routes should move from stand-alone reviews to risk-based models. However, this study indicated that there would be challenges to implement this approach in practice, which would include improving resource capacity and the number of expert reviewers as well as implementing electronic tracking systems.

A Retrospective Analysis of Applications for Registration of Generic Medicines Processed by the Medicines Control Authority of Zimbabwe.

BACKGROUND: Many applications for registration of medicines are rejected because applicants fail to submit or resolve critical deficiencies in the quality, efficacy, and safety of the medicines. The study aimed to establish approval rates, processing timelines, and common deficiencies of generic medicines applications processed by the Medicines Authority of Zimbabwe (MCAZ). METHOD: A retrospective study of applications finalized by MCAZ between 2018 and 2020 was conducted. Data were collected from the assessment reports and verified with copies of letters sent to the applicants. Deficiencies were classified as administrative, quality, efficacy, and safety. Other characteristics collated included time to finalization, dosage form, region of origin, and therapeutic class. RESULTS: Of the 579 finalized applications, 74.1% were approved while 25.9% were refused. Approved applications had more review cycles (median = 3 cycles) compared to refused applications (median = 2 cycles). However, refused applications had longer review times (median = 25 months) compared to approved applications (median = 18 months). The majority of applications (83.0%) were from Asian manufacturers and intended for oral administration (66.1%). Medicines for the endocrine system (50.0%) and rheumatism/gout (53.3%) had lower approval rates compared to other therapeutical classes (p < 0.001). The most common reasons for refusal of applications included failure to respond to review queries (52.6%), deficiencies in the API information (54.7%), FPP specifications (42.7%), FPP stability data (36.0%), and pharmaceutical development (31.3%). CONCLUSION: To improve the quality of applications and evaluation outcomes, there may be a need for the regulatory authority to engage applicants through training and pre-submission meetings.

Pharmaceutical Industry Evaluation of the Effectiveness and Efficiency of the ZaZiBoNa Collaborative Medicines Registration Initiative: The Way Forward.

Introduction: The common technical document (CTD) format harmonised the requirements for the registration of medicines, which had traditionally differed from country to country, making it possible for countries to collaborate and conduct joint reviews of applications. One such collaborative medicines registration initiative is the Southern African Development Community ZaZiBoNa, established in 2013. A recent study was carried out with the nine active member regulatory authorities of the ZaZiBoNa to determine their views on its operational effectiveness and efficiency. Having obtained the authorities' views, the aim of this study was to evaluate the effectiveness and efficiency of the current operating model of the ZaZiBoNa initiative including the challenges it faces as well as identifying opportunities for improvement from the applicants' perspective. Methods: Applicants who had submitted registration/marketing authorisation applications for assessment under the ZaZiBoNa initiative during 2017-2021 were recruited into the study. Data was collected in 2021 using the Process, Effectiveness and Efficiency rating questionnaire (PEER-IND) developed by the authors. The questionnaire was completed by a representative responsible for ZaZiBoNa submissions in each company. Results: The pharmaceutical industry was of the view that the ZaZiBoNa initiative has achieved shorter timelines for approval of medicines, resulting in increased availability of quality-assured medicines for patients in the SADC region. Harmonisation of registration requirements and joint reviews have reduced the workload for both the pharmaceutical industry and the regulatory authorities. Some of the challenges identified were the lack of a centralised submission and tracking system, and the lack of information for applicants on the process for submission of ZaZiBoNa dossiers/applications in the individual countries, including contact details of the focal person. The establishment of a regional unit hosted in one of the member countries to centrally receive and track ZaZiBoNa dossiers/applications was identified as the best strategy for moving forward in the interim with the long-term goal being the establishment of a regional medicines authority. Conclusion: There was consensus between the pharmaceutical industry and the regulatory authorities as to the way forward to improve the effectiveness and efficiency of the ZaZiBoNa initiative. Implementation of the recommendations identified in this study will lead to enhanced regulatory performance.

Regulatory Authority Evaluation of the Effectiveness and Efficiency of the ZaZiBoNa Collaborative Medicines Registration Initiative: The Way Forward.

Introduction: ZaZiBoNa, the work-sharing initiative in the Southern African Development Community (SADC) that has been in operation for 8 years has successfully assessed over 300 dossiers/applications, with an overall median time to recommendation of 12 months. All 16 SADC countries participate in the initiative as either active or non-active members. While the successes of ZaZiBoNa are evident, some challenges still exist. The aim of this study was to solicit the views of the participating authorities on the effectiveness and efficiency of the current operating model of the ZaZiBoNa initiative. Methods: Data were collected in 2021 using the Process, Effectiveness and Efficiency Rating (PEER) questionnaire developed by the authors. The questionnaire was completed by the focal person in each country and approved by the head of the authority. Results: ZaZiBoNa serves as a platform for work sharing, information exchange, capacity building and harmonisation of registration requirements. One of the benefits to regulators has been the improvement in the capacity to conduct assessments. Manufacturers have benefited from compiling one package (modules 2-5) for the initial submission as well as a single response package to the consolidated list of questions, which saves time and resources. Respondents were of the view that patients have benefited as the ZaZiBoNa has contributed to an improved availability and accessibility to quality-assured medicines. Some of the challenges identified were the inadequacy of resources and differences in time to the implementation of ZaZiBoNa recommendations by the individual countries. The establishment of a regional unit hosted in one of the member countries to enable centralised submission and coordination was identified as the best strategy to improve the effectiveness and efficiency of the initiative in the interim, with the long-term goal being the establishment of a regional medicines authority. Conclusion: The study identified the strengths of the ZaZiBoNa initiative as well as the opportunities for improvement. The recommendations made would further strengthen this initiative.

Comparison of the registration process of the medicines control authority of Zimbabwe with Australia, Canada, Singapore, and Switzerland: benchmarking best practices.

BACKGROUND: Benchmarking regulatory systems of low- and middle-income countries with mature systems provides an opportunity to identify gaps, enhance review quality, and reduce registration timelines, thereby improving patients' access to medicines. The aim of this study was to compare the medicines registration process of the Medicines Control Authority of Zimbabwe (MCAZ) with the regulatory processes in Australia, Canada, Singapore, and Switzerland. METHODS: A questionnaire that standardizes the review process, allowing key milestones, activities and practices of the five regulatory authorities was completed by a senior member of the divisions responsible for issuing marketing authorizations. RESULTS: The MCAZ has far fewer resources than the regulatory authorities in the comparator countries, but employs three review models, which is in line with international best practice. The MCAZ registration process is similar to the comparator countries in key milestones monitored, but differs in the target timelines for these milestones. The MCAZ is comparable to the comparator authorities in implementing the majority of good review practices, although it significantly lags behind in transparency and communication. CONCLUSION: This study identified the MCAZ strengths and opportunities for improvement, which if implemented, will enable the achievement of its vision to be a leading regulatory authority in Africa.

Evaluation of the Good Review Practices of Countries Participating in the Southern African Development Community: Alignment and Strategies for Moving Forward.

Introduction: National medicines regulatory agencies are faced with challenges including limited resources and technical capacity, resulting in countries collaborating and sharing resources to improve efficiency of the review process to facilitate access to quality-assured medicines by their populations. One such collaboration is the Southern African Development Community (SADC) medicines registration collaborative initiative, ZaZiBoNa. Countries participate in the initiative by contributing to regulatory reviews and good manufacturing practices inspections. The aim of this study was to review and compare the registration processes of regulatory authorities of Mozambique, Namibia, South Africa, Tanzania, Zambia, and Zimbabwe to identify strategies for better alignment. Methods: A senior member of the division responsible for issuing marketing authorisations completed an established and validated questionnaire, which standardises the review process, allowing key milestones, activities and practices of the six regulatory authorities to be identified and compared. The completed questionnaires were validated by the heads of the respective agencies. Results: The six countries vary in population and in the size of their respective regulatory agency and the resources allocated to regulatory reviews. The review processes of the six agencies were similar; however, differences were noted in the milestones recorded; for example, two of the countries did not record the start of the scientific assessment. Additionally, decisions for marketing authorisation were made by an expert committee in four of the countries and by the head of the agency and the Minister of Health in two countries. All six agencies implemented the majority of good review practices; however, the need for improvement in the areas of transparency and communication and quality decision making practices was a common finding for all six countries. Conclusions: Participation in the ZaZiBoNa initiative has improved the way in which the six agencies perform regulatory reviews in their countries, highlighting the realisation of one of the key objectives of the initiative, which was building the expert capacity of member countries. Other agencies in the SADC region and beyond can use the results of this study to identify best practices, which in turn, could improve their regulatory performance.

Evaluation of the Review Models and Approval Timelines of Countries Participating in the Southern African Development Community: Alignment and Strategies for Moving Forward.

Introduction: Regulatory reliance, harmonization and work sharing have grown over the last few years, resulting in greater sharing of work and information among regulators, enabling efficient use of limited resources and preventing duplication of work. Various initiatives on the African continent include ZaZiBoNa, the Southern African Development Community (SADC) collaborative medicines registration initiative. ZaZiBoNa has resulted in great savings in time and resources; however, identified challenges include lack of clear information regarding the participating countries registration processes and requirements as well as lengthy registration times. The aim of this study, therefore, was to compare the data requirements and review models employed in the assessment of applications for registration, the target timelines for key milestones and the metrics of applications received and approved in 2019 and 2020 by Mozambique, Namibia, South Africa, Tanzania, Zambia, and Zimbabwe. Methods: A senior member of the division responsible for issuing marketing authorisations completed an established and validated questionnaire, which standardizes the review process, allowing key milestones, activities and practices of the six regulatory authorities to be identified and compared. The completed questionnaires were validated by the heads of the respective agencies. Results: The majority of applications received and approved by all six agencies in 2019 and 2020 were for generics. The mean approval times for generics varied across the countries, with ranges of 218-890 calendar days in 2019 and 158-696 calendar days in 2020. All three types of scientific assessment review models were used by the six agencies and data requirements and extent of scientific assessment were similar for five countries, while one conducted full reviews for new active substances. A large variation was observed in the targets set by the six agencies for the different milestones as well as overall approval times. Conclusions: The study identified the strengths of the countries as well as opportunities for improvement and alignment. Implementation of the recommendations made as in this study will enhance the countries' individual systems, enabling them to efficiently support the ZaZiBoNa initiative.

Evaluation of the Regulatory Review Process in Zimbabwe: Challenges and Opportunities.

PURPOSE: The aims of this study were to assess the current regulatory review process of the Medicines Control Authority of Zimbabwe (MCAZ), identify key milestones and target timelines, evaluate the overall performance from 2017 to 2019, identify good review practices, evaluate the quality of decision-making processes, and identify the challenges and opportunities for improvement. METHODS: A questionnaire was completed by the MCAZ. The agency has participated in the Optimising Efficiencies in Regulatory Agencies (OpERA) program, a multinational endeavor to characterize assessment procedures and metrics associated with regulatory agencies and regional regulatory initiatives. Data identifying the milestones and overall approval times for all products registered MCAZ from 2017 to 2019 were collected and analyzed. RESULTS: The MCAZ conducts a full review of quality, safety, and efficacy data for generics and biosimilars not approved by a reference agency, an abridged review for products approved by a reference agency and a verification review for World Health Organization prequalified products under the collaborative registration procedure. The highest number of reviewed products is generics manufactured by foreign companies. There has been an improvement in review times for all categories of products over the three-year period. Guidelines, standard operating procedures, and review templates are in place and the majority of indicators for good review practices are implemented. Although quality decision-making practices are implemented, there is no formal framework in place. CONCLUSION: The MCAZ successfully implements three types of review models in line with international standards. Overall, target timelines are realistic and what is achievable with the current available resources. Recommendations made such as the review of available human resources, separation of agency and company time when setting and measuring targets, review of the templates and benefit-risk framework used for abridged review, and development of a decision-making framework present opportunities for an enhanced regulatory review process.

Evaluating the Success of ZaZiBoNa, the Southern African Development Community Collaborative Medicines Registration Initiative.

The Southern African Development Community (SADC) collaborative medicines registration initiative ZaZiBoNa is a successful regional work-sharing initiative on the African continent. This paper reviews the history of the ZaZiBoNa initiative, reflects on what has been realized in six years of operation and what still needs to be achieved. Statistics for the work done by the initiative are available in the literature, but there has not been a critical review of the process, including an analysis of factors contributing to the success of the initiative and conversely those negatively affecting performance. To do this, publicly available literature and statistics, meeting records, terms of reference and unpublished documents belonging to the initiative were reviewed. The successes of the ZaZiBoNa initiative can be attributed to leadership commitment, a clear vision and governance structure providing direction, and a clear, documented operating model, processes and objectives defined from the onset of the initiative. Closure of the gaps that were identified and implementation of the recommendations that were made in this paper will further strengthen the initiative. Furthermore, other regional harmonization or work-sharing initiatives on the African continent and beyond can draw lessons from this review of the ZaZiBoNa initiative for improved efficiency and effectiveness.

Regulating the pH of bicarbonate solutions without purging gases: Application to dissolution testing of enteric coated tablets, pellets and microparticles.

Dissolution media based on bicarbonate buffers closely mimic the environment of intestinal fluids and thus improve in vitro in vivo correlation compared to phosphate buffers. Purging gases into the medium is used as a method to stabilise bicarbonate buffers; however, this causes issues due to the disturbance of the hydrodynamics in the dissolution vessel. The aim of this study was to develop a novel system to regulate and stabilise the pH of bicarbonate buffers without purging gases for the application of dissolution testing of enteric coated products. A novel enclosure system was applied to the USP II dissolution vessel to supply N2 and CO2 gases above the dissolution medium without purging into the solution. Drug release from enteric coated predinisolone microparticles (216.9 µm), pellets (1.25 mm) and commercially available tablets was determined in 0.1 M HCl and subsequently in pH 6.8 phosphate buffer or pH 6.2-6.8 bicarbonate buffers generated by titration of the acidic medium in situ using USP II apparatus. Supplying N2 at 3-4 bar and CO2 at 0.1 bar were able to increase the pH of the bicarbonate buffer from pH 6.2 to 6.8 within 45 min and subsequently stabilise the medium pH at 6.8 ± 0.05 pH units. Enteric coated microparticles showed much faster drug release in the physiological bicarbonate buffers than tablets and pellets. The novel bicarbonate-based dissolution system moves forward the application of the physiological bicarbonate buffers for testing pharmaceutical products to meet compendial requirements.