A Quality by Design Approach for Optimizing Solid Lipid Nanoparticles of Bedaquiline for Improved Product Performance.

Bedaquiline (BQ) solid lipid nanoparticles (SLNs), which have previously been formulated for parenteral administration, have a risk of patient non-compliance in treating tuberculosis. This research presents a strategy to develop BQ SLNs for oral delivery to improve patient adherence, The upper and lower levels for the formulation excipients were generated from screening experiments. Using 4 input factors (BQ, lecithin, Tween 80, and PEG), a full factorial design from 3 × 2x2 × 2 experiments was randomly arranged to investigate 3 response variables: Particle size distribution (PSD), polydispersity index (PdI), and zeta potential (ZP). High shear homogenization was used to mix the solvent and aqueous phases, with 15% sucrose as a cryoprotectant. The response variables were assessed using a zeta sizer while TEM micrographs confirmed the PSD data. Solid-state assessments were conducted using powdered X-ray diffraction and scanning electron microscopy (SEM) imaging. A comparative invitro assessment was used to determine drug release from an equivalent dose of BQ free base powder and BQ-SLN, both packed in hard gelatin capsules. The sonicated formulations obtained significant effects for PSD, PdI, and ZP. The p-values (0.0001 for PdI, 0.0091 for PSD) for BQ as an independent variable in the sonicated formulation were notably higher than those in the unsonicated formulation (0.1336 for PdI, 0.0117 for PSD). The SEM images were between 100 - 400 nm and delineated nanocrystals of BQ embedded in the lipid matrix. The SLN formulation provides higher drug levels over the drug's free base; a similarity factor (f2 = 18.3) was estimated from the dissolution profiles.

Transfer learning predicts species-specific drug interactions in emerging pathogens.

Machine learning (ML) algorithms are necessary to efficiently identify potent drug combinations within a large candidate space to combat drug resistance. However, existing ML approaches cannot be applied to emerging and under-studied pathogens with limited training data. To address this, we developed a transfer learning and crowdsourcing framework (TACTIC) to train ML models on data from multiple bacteria. TACTIC was built using 2,965 drug interactions from 12 bacterial strains and outperformed traditional ML models in predicting drug interaction outcomes for species that lack training data. Top TACTIC model features revealed genetic and metabolic factors that influence cross-species and species-specific drug interaction outcomes. Upon analyzing ~600,000 predicted drug interactions across 9 metabolic environments and 18 bacterial strains, we identified a small set of drug interactions that are selectively synergistic against Gram-negative (e.g., A. baumannii) and non-tuberculous mycobacteria (NTM) pathogens. We experimentally validated synergistic drug combinations containing clarithromycin, ampicillin, and mecillinam against M. abscessus, an emerging pathogen with growing levels of antibiotic resistance. Lastly, we leveraged TACTIC to propose selectively synergistic drug combinations to treat bacterial eye infections (endophthalmitis).

Synthesis, Characterization, and Stability Assessment for the Benzoate, Hydrochloride, Malonate, and Nicotinate Salts of Bedaquiline.

Bedaquiline has been approved as a combination therapy to treat multi-drug-resistant tuberculosis in adults ≥ 18 years old. The citrate, fumarate, phosphate, and tartrate salts have obtained patents, but the structures for these moieties have not been extensively described in the literature; only the powder X-ray patterns have been published. To expand the knowledge of the bedaquiline structure, this study provides detailed information for the synthesis, elucidation, characterization, and stability of four additional new potential molecular entities, namely, benzoate, hydrochloride (HCl), nicotinate, and malonate salts. The salts were formed using a 1:1 ratio of the counter ions (acids) to a 30 mg equivalent of the bedaquiline free base. The principles of the International Conference on Harmonization Q6 were used to characterize the new salts and their stability-indicating parameters were evaluated at 0, 3, and 6 months under accelerated conditions of 40 °C and 75% relative humidity. The benzoate salt exhibited the lowest tendency to lose its chemical potency. Aside from the HCl salt, the others retained their chemical structure, displaying long-term stability. All salts were non-hygroscopic and the hydrated benzoate and nicotinate salts were stable to dehydration. Regarding their chemical potencies, thermal analysis, chemical stability, and water sorption potential, the salts were ranked as follows: benzoate > malonate > nicotinate > HCl.

Potency and Powder X-ray Diffraction (PXRD) Evaluation of Levothyroxine Sodium Tablets under Ambient, Accelerated, and Stressed Conditions.

Levothyroxine tablets, although highly prescribed in the United States, have been one of the most frequently recalled products. Because of the importance of the medication, several efforts have been put in place by the United States Food and Drug Administration (US FDA) to control the quality of levothyroxine tablets available to patients using the drug. The choice of excipients used in the formulation has been shown to impact the hygroscopicity and microenvironment, and ultimately the stability of the levothyroxine tablets formulations. Based on information generated from the US FDA Enforcement Report database, one of the main reasons for recalls is the low potency of different batches of the product. The yearly product recall trends for levothyroxine formulations were determined using the FDA Enforcement Report database. Three brands of levothyroxine tablets were selected with excipient lists similar to those products that have been historically recalled. The samples were placed at ambient (~23 °C), accelerated stability (40 °C/75% RH), and stress (50 °C/75% RH) conditions for up to 6 months. Sample potencies were determined at 0, 1.5, 3, and 6 months using the methods for assay and impurities in the United States Pharmacopeia (USP) monograph for levothyroxine tablets. Additional sample monitoring was conducted by overlaying the initial powder X-ray diffractograms (PXRD) of the samples from 0 months with the patterns generated thereafter. There has been a decline in the number of levothyroxine tablets recalled over the years. The highest numbers of recalls were recorded in the years 2013 [33] and 2020 [23]; no recalls occurred in the years 2019 and 2022. All of the brands evaluated met the USP 95.0-105.0% assay requirements at 1.5 months under accelerated conditions; only one of the brands complied at 3 months. Under ambient conditions, two brands were stable at 6 months, with borderline assay results. For stability, levothyroxine was found in microgram quantities in the formulations and PXRD could not detect changes at these low levels. However, we found some distinguishing data for samples under stress conditions.

Determining the solubilities for benzoate, nicotinate, hydrochloride, and malonate salts of bedaquiline.

Determining the solubility of a compound is important for predicting its oral bioavailability, the medium to be used for dissolution, and solvents for cleaning during manufacturing. The solubilities of the newly synthesized benzoate, hydrochloride, nicotinate, and malonate salts of bedaquiline were elucidated, and the plausible reasons for the differences observed in their experimental aqueous solubilities were highlighted. The shake flask method was used to determine the experimental solubilities of the bedaquiline free base and all the salts in water, 0.01 N HCl, and pH 6.8 buffer. The molar and mole fraction solubility estimates of the salts were determined using equations for ideal and non-ideal situations. Furthermore, the relative contribution of the lattice and activity coefficient to the overall aqueous solubility of the salts were predicted graphically. The new salts ranked hydrochloride [0.6437 mg/mL] > malonate [0.0268 mg/ml] > nicotinate [0.0024 mg/mL] > benzoate [0.0004 mg/mL], showed improved aqueous solubility over the free base. The general solubility equation [GSE], fairly predicted the solubilities for the benzoate and malonate salts, but the ideal solubility equations provided poor estimates of their experimental values. Based on the ideal solubility estimates, the crystal lattice contributions of all salts were malonate > nicotinate > HCl > benzoate. However, using the activity coefficient values, the order of hydrophobicity of the bedaquiline salts was: benzoate > nicotinate > malonate > HCl. The salts forms of bedaquiline offered additional solubility as a function of their crystallinity and hydrophobicity.

Impact of ISO/IEC 17025 laboratory accreditation in sub-Saharan Africa: a case study.

BACKGROUND: The number and severity of nonconformities generated during an audit of a medicine testing laboratory indicates its level of quality compliance. Quality standards are established and maintained to ensure the reliability of laboratory test reports. The National Medicines Regulatory Authority (NMRA) Quality Control laboratories assess the quality of medicines used by the populace as part of their regulatory function. Although countries desire to have reliable medicine testing facilities, accrediting a national laboratory to international standards poses financial and technical challenges for many low-income countries. Sharing the benefits of laboratory accreditation could help more countries within sub-Saharan Africa overcome existing challenges to achieve accreditation and robust quality systems. This study investigated the impact of ISO/IEC 17025 accreditation on the performance of an NMRA Quality Control laboratory to provide evidence of improved quality compliance within a low-resource setting. METHODS: Pre- and post- accreditation audits of nonconformities for management and technical requirements of the ISO/IEC17025:2005 standards were evaluated from a Quality Control laboratory in the National Agency for Food and Drug Administration and Control (NAFDAC), located in Nigeria, West Africa. The following research questions were addressed: "does accreditation impact the adherence to quality standards?" and "does accreditation decrease the severity of nonconformities in Quality Control laboratory audits?" RESULTS: Statistical analysis of the pre- to post- accreditation audits from the years 2013 through 2017 revealed a significant decrease in the total number of nonconformities (χ2 = 74, p-value = 9.99e-05, r = 0.67). Further examination of audits from the years 2013 through 2018 audits also revealed a reduction in the number of nonconformities (χ2 = 53, p-value = 9.99e-05, r = 0.62). A reduction in the number of major observations and a decrease in the severity of nonconformities was also observed. CONCLUSIONS: A higher level of quality compliance was exhibited for the laboratory during the post-accreditation years. Overall, ISO/IEC 17025 accreditation of the NMRA Quality Control laboratory resulted in improved reliability of test reports and enhancement of the laboratory quality system.