Adjusted Indirect Treatment Comparison of the Bioavailability of WHO-Prequalified First-Line Generic Antituberculosis Medicines

High-Speed Tableting of High Drug-Loaded Tablets Prepared from Fluid-Bed Granulated Isoniazid

The aim of this feasibility study was to investigate the possibility of producing industrial-scale relevant, robust, high drug-loaded (90.9%, w/w) 100 mg dose immediate-release tablets of isoniazid and simultaneously meet the biowaiver requirements. With an understanding of the real-life constrictions on formulation scientists during product development for the generic industry, this study was done considering a common set of excipients and manufacturing operations, as well as paying special attention to the industrial-scale high-speed tableting process as one of the most critical manufacturing operations. The isoniazid substance was not applicable for the direct compression method. Thus, the selection of granulation method was logically justified, and it was fluid-bed granulated with an aqueous solution of Kollidon^® 25, mixed with excipients, and tableted with a rotary tablet press (Korsch XL 100) at 80 rpm (80% of the maximum speed) in the compaction pressure range 170-549 MPa monitoring of ejection/removal forces, tablet weight uniformity, thickness, and hardness. Adjusting the main compression force, the Heckel plot, manufacturability, tabletability, compactability, and compressibility profiles were analysed to choose the main compression force that resulted in the desirable tensile strength, friability, disintegration, and dissolution profile. The study showed that highly robust drug-loaded isoniazid tablets with biowaiver requirements compliance can be prepared with a common set of excipients and manufacturing equipment/operations incl. the industrial-scale high-speed tableting process.

Situation analysis on the regulation of nanomedicines in Southern Africa

Background

Medical products incorporating nanoparticle drug delivery systems (nanomedicines) are therapeutic or imaging agents, which comprise a delivery system within the nanometer size range (1 - 1000 nm). As medical products, nanomedicines meet definitions of medicines according to various national legislations for regulation of medicines. However, for the regulation of nanomedicines, additional assessments including toxicological issues have to be considered. These complexities require extra regulatory effort. In the resource-limited context of low- and middle-income countries, many National Medicines Regulatory Authorities (NMRAs) lack resources and capacities to effectively assure the quality of medicinal products in their countries. With emerging trends in innovative technologies, including nanotechnology, this burden is worsened. The need to overcome regulatory challenges drove the formation of a work sharing initiative in the Southern African Development Community (SADC), ZaZiBoNA in 2013. Regulatory agencies participating in this initiative cooperate in the assessment of applications for registration of medicines.

Methods

A cross-sectional exploratory study design with qualitative techniques was used to investigate the status of the regulation of nanomedicines in Southern African countries in particular those participating in the ZaZiBoNA initiative.

Results

The study found that in general, NMRAs are aware of the existence of nanomedicines and they apply legislation applicable to other medical products. The NMRAs however neither have specific definition for nanomedicines and technical guidance documents, nor technical committees specific for consideration of nanomedicines. Collaboration with external experts or organisations in the regulation of nanomedicines was also found to be lacking.

Discussion

Capacity building and collaboration in the area of regulation of nanomedicines is strongly encouraged.

Evidence-based public policy making for medicines across countries: findings and implications for the future

Aim: Global expenditure on medicines is rising up to 6% per year driven by increasing prevalence of non-communicable diseases (NCDs) and new premium priced medicines for cancer, orphan diseases and other complex areas. This is difficult to sustain without reforms. Methods: Extensive narrative review of published papers and contextualizing the findings to provide future guidance. Results: New models are being introduced to improve the managed entry of new medicines including managed entry agreements, fair pricing approaches and monitoring prescribing against agreed guidance. Multiple measures have also successfully been introduced to improve the prescribing of established medicines. This includes encouraging greater prescribing of generics and biosimilars versus originators and patented medicines in a class to conserve resources without compromising care. In addition, reducing inappropriate antibiotic utilization. Typically, multiple measures are the most effective. Conclusion: Multiple measures will be needed to attain and retain universal healthcare.

Adjusted indirect comparisons to assess bioequivalence between generic clopidogrel products in Serbia

AIMS

Generic products can be regarded as therapeutically equivalent and switchable with the reference product. However, switchability between generics is unknown, as direct comparisons between generics are not performed. The aim of this study was to investigate the bioequivalence between generic clopidogrel products by means of adjusted indirect comparisons (AICs).

METHODS

AICs were conducted to assess bioequivalence between 4 generic clopidogrel products that are authorised in Serbia. Generics are considered equivalent to the reference if the 90% confidence intervals (CIs) for the ratios test/reference of the maximum concentration (C_max ) and area under the curve up to the last measurable concentration (AUC_0-t ) fall within the acceptance range 80.00-125.00%. However, for AICs between generics, the Canadian acceptance criterion for C_max was employed, where only the point estimate of C_max needs to be within 80.00-125.00%.

RESULTS

The 90% CIs of the AICs demonstrated bioequivalence within 80.00-125.00% for all AUC_0-t comparisons. The point estimates of C_max in all AICs were also within this range.

CONCLUSION

This study demonstrates that the bioavailability of these 4 generic clopidogrel products authorised in Serbia is very similar. Despite the limited power of AICs, bioequivalence was demonstrated for all 90% CIs of AUC_0-t and all 90% CIs of C_max comparisons were within or very close to the acceptance range, being able to comply with the acceptance criterion employed in Canada for C_max . Therefore, these 4 generic clopidogrel products authorised in Serbia can be considered switchable with each other in clinical practice based on the adjusted indirect comparisons.

Evaluating the Feasibility of Use of a Foreign Reference Product for Generic Drug Applications: A Retrospective Pilot Study

BACKGROUND AND OBJECTIVES

The adoption of a domestic reference product in bioequivalence (BE) studies for generic drug applications is required by some countries. The objective of this study is to assess the feasibility of this by investigating whether innovative products from different countries are bioequivalent.

METHODS

Data were collected from all generic drug applications received by the Taiwan regulatory authority 2012-2016. If a submission package contained BE studies, that generic product was compared separately with different reference products, and the resulting data included in this analysis. A method of adjusted indirect comparison was used to evaluate the BE of reference products from different sources. The relationship between in vitro dissolution and in vivo BE was also explored.

RESULTS

The present study included 10 drugs and a total of 11 comparisons. Seven comparisons for maximum concentration (C _max) (63.6%) and all comparisons (100.0%) for area under the curve up to last measurable time point (AUC) complied with the BE criterion. Similar in vitro dissolution profiles were observed in all comparisons. Among the comparisons that failed to demonstrate BE, only one was considered to be possibly related to product difference, with point estimates of indirect comparison for C _max significantly greater than unity (22%). Discordance between in vitro and in vivo observations was probably due to either drugs with highly variable properties or a lack of discriminatory dissolution testing method.

CONCLUSIONS

Although this retrospective analysis only included a few drugs and product formulation types, i.e., immediate release, delayed release, and orally disintegrating tablet, these preliminary results suggest that using a foreign reference product in BE studies for generic drug applications could be a feasible approach, but with some restrictions: comparable dissolution profiles, same innovator company, same size, weight, and type of coating as the domestic reference product, etc. Further investigations for other complex formulations are required.

Interchangeability between first-line generic antiretroviral products prequalified by WHO using adjusted indirect comparisons

BACKGROUND

The scaling-up of access to antiretroviral therapy, particularly in low- to middle-income countries, was facilitated by the introduction and widespread use of generic antiretroviral medicines and fixed-dose combinations. Generic medicines are approved by regulatory authorities based on the demonstration of bioequivalence with the innovator or reference product, as well as meeting quality standards. In clinical practice, however, it is not unusual for generics to be interchanged between each other. This study investigated the differences in bioavailability between WHO-prequalified first-line antiretroviral generics by means of adjusted indirect comparisons to ensure interchangeability between these generics.

METHODS

Data on 34 products containing emtricitabine, tenofovir disoproxil fumarate, lamivudine and efavirenz in single formulations or fixed-dose combinations were included in the analysis. The 90% CI for the adjusted indirect comparisons was calculated using the homoscedastic method that uses the conventional t-test, and assumes homogeneity of variances between the studies and small sample sizes. The combined standard deviation of both bioequivalence studies was calculated from the variability of each individual study.

RESULTS

The adjusted indirect comparisons between generics showed that the differences, expressed as 90% CIs, are less than 30%. Confidence in the interchangeability of two generic products was reduced if the mean difference between the test and reference in the original studies is more than 10%.

CONCLUSIONS

From a bioequivalence perspective, the generic antiretroviral medicines prequalified by WHO are interchangeable with the reference, as well as between each other without safety or efficacy concerns.

The combined fixed-dose antituberculous drugs alter some reproductive functions with oxidative stress involvement in wistar rats

The reproductive toxicity of combined fixed-dose first-line antituberculosis (CFDAT) regimen was assessed in rats. Thirty-two (32) Wistar rats weighing 168.1 ± 8.0 g were divided into four groups of eight rats per group. Two groups of male and female rats were administered oral distilled water (1.6 ml) and CFDAT drugs containing rifampicin, isoniazid, pyrazinamide and ethambutol (RIPE, 92.5 mg/m2 per body surface area) respectively for forty-five days. Serum follicle stimulating hormone, luteinizing and testosterone were reduced significantly (p < 0.05) in the treated male rats. Similarly, sperm count levels were decreased by 27.3% when compared with control. RIPE elevated serum oestrogen (p < 0.05), progesterone (p < 0.05) as well as prolactin (p > 0.05) levels in the treated females. In addition, RIPE reduced (p < 0.05) total proteins levels and increased (p < 0.05, 53%) catalase levels in male but not female animals. Superoxide dismutase, glutathione-S-transferase, glutathione peroxidase, reduced glutathione levels as well as lipid peroxidation were unaltered in all rats respectively. Histopathological studies revealed congested peritesticular vessels and no changes in the ovary when compared with control. Overall, our results demonstrate reproductive toxicity potentials of RIPE in the rat, thus, suggesting that these reproductive parameters be monitored during antituberculous chemotherapy.