Unique Risks, Benefits, and Challenges of Developing Drug-Drug Combination Products in a Pharmaceutical Industrial Setting

Multi-task learning for predicting synergistic drug combinations based on auto-encoding multi-relational graphs

Combinatorial drug therapy is a promising approach for treating complex diseases by combining drugs with synergistic effects. However, predicting effective drug combinations is challenging due to the complexity of biological systems and the limited understanding of pathophysiological mechanisms and drug targets. In this paper, we proposed a computational framework called VGAETF (Variational Graph Autoencoder Tensor Decomposition), which leveraged multi-relational graph to model complex relationships between entities in biological systems and predicted disease-related synergistic drug combinations in an end-to-end manner. In the computational experiments, VGAETF achieved high performances (AUROC [the area under receiver operating characteristic] = 0.9767, AUPR [the area under precision-recall] = 0.9660), outperforming other compared methods. Moreover, case studies further demonstrated the effectiveness of VGAETF in identifying potential disease-related synergistic drug combinations.

Dipeptide Nitrile CD34 with Curcumin: A New Improved Combination Strategy to Synergistically Inhibit Rhodesain of Trypanosoma brucei rhodesiense

Rhodesain is the main cysteine protease of Trypanosoma brucei rhodesiense, the parasite causing the acute lethal form of Human African Trypanosomiasis. Starting from the dipeptide nitrile CD24, the further introduction of a fluorine atom in the meta position of the phenyl ring spanning in the P3 site and the switch of the P2 leucine with a phenylalanine led to CD34, a synthetic inhibitor that shows a nanomolar binding affinity towards rhodesain (K_i = 27 nM) and an improved target selectivity with respect to the parent dipeptide nitrile CD24. In the present work, following the Chou and Talalay method, we carried out a combination study of CD34 with curcumin, a nutraceutical obtained from Curcuma longa L. Starting from an affected fraction (f_a) of rhodesain inhibition of 0.5 (i.e., the IC₅₀), we observed an initial moderate synergistic action, which became a synergism for f_a values ranging from 0.6 to 0.7 (i.e., 60-70% inhibition of the trypanosomal protease). Interestingly, at 80-90% inhibition of rhodesain proteolytic activity, we observed a strong synergism, resulting in 100% enzyme inhibition. Overall, in addition to the improved target selectivity of CD34 with respect to CD24, the combination of CD34 + curcumin resulted in an increased synergistic action with respect to CD24 + curcumin, thus suggesting that it is desirable to use CD34 and curcumin in combination.

Drug Combination Studies of the Dipeptide Nitrile CD24 with Curcumin: A New Strategy to Synergistically Inhibit Rhodesain of Trypanosoma brucei rhodesiense

Rhodesain is a cysteine protease that is crucial for the life cycle of Trypanosoma brucei rhodesiense, a parasite causing the lethal form of Human African Trypanosomiasis. CD24 is a recently developed synthetic inhibitor of rhodesain, characterized by a nanomolar affinity towards the trypanosomal protease (Ki = 16 nM), and acting as a competitive inhibitor. In the present work, we carried out a combination study of CD24 with curcumin, the multitarget nutraceutical obtained from Curcuma longa L., which we demonstrated to inhibit rhodesain in a non-competitive manner. By applying the Chou and Talalay method, we obtained an initial additive effect at IC50 (fa = 0.5, Combination Index = 1), while for the most relevant fa values, ranging from 0.6 to 1, i.e., from 60% to 100% of rhodesain inhibition, we obtained a combination index < 1, thus suggesting that an increasingly synergistic action occurred for the combination of the synthetic inhibitor CD24 and curcumin. Furthermore, the combination of the two inhibitors showed an antitrypanosomal activity better than that of CD24 alone (EC50 = 4.85 µM and 10.1 µM for the combination and CD24, respectively), thus suggesting the use of the two inhibitors in combination is desirable.

Multidrug resistance crisis during COVID-19 pandemic: Role of anti-microbial peptides as next-generation therapeutics

The decreasing effectiveness of conventional drugs due to multidrug-resistance is a major challenge for the scientific community, necessitating development of novel antimicrobial agents. In the present era of coronavirus 2 (COVID-19) pandemic, patients are being widely exposed to antimicrobial drugs and hence the problem of multidrug-resistance shall be aggravated in the days to come. Consequently, revisiting the phenomena of multidrug resistance leading to formulation of effective antimicrobial agents is the need of the hour. As a result, this review sheds light on the looming crisis of multidrug resistance in wake of the COVID-19 pandemic. It highlights the problem, significance and approaches for tackling microbial resistance with special emphasis on anti-microbial peptides as next-generation therapeutics against multidrug resistance associated diseases. Antimicrobial peptides exhibit exceptional mechanism of action enabling rapid killing of microbes at low concentration, antibiofilm activity, immunomodulatory properties along with a low tendency for resistance development providing them an edge over conventional antibiotics. The review is unique as it discusses the mode of action, pharmacodynamic properties and application of antimicrobial peptides in areas ranging from therapeutics to agriculture.

Small Molecule, Multimodal, [18F]-PET and Fluorescence Imaging Agent Targeting Prostate-Specific Membrane Antigen: First-in-Human Study

BACKGROUND

A first-in-human study of [¹⁸F]-BF3-Cy3-ACUPA, a small-molecule contrast agent that can be unimolecularly both positron emitting and fluorescent, is conducted to determine its: its safety, biodistribution, radiation dosimetry, feasibility in tumor detection by preoperative positron emission tomography (PET), as well as its intraoperative fluorescence imaging utility in patients with prostate-specific membrane antigen positive (PSMA⁺) tumors.

METHODS

Ten patients aged 66 ± 7 years received a 6.5 ± 3.2 mCi intravenous injection of [¹⁸F]-BF3-Cy3-ACUPA and underwent PET/computed tomography (CT) imaging. Radiation dosimetry of [¹⁸F]-BF3-Cy3-ACUPA, normal organ biodistribution, and tumor uptakes were examined. Two patients were prescheduled for radical prostatectomy (RP) with extended pelvic lymphadenectomy approximately 24 hours following [¹⁸F]-BF3-Cy3-ACUPA injection and imaging. Without reinjection, intraoperative fluorescence imaging was performed on freshly excised tissue during RP. Frozen sections of excised tissue during RP were submitted for confirmatory histopathology and multiphoton fluorescence and brightfield microscopy.

RESULTS

Absorbed doses by organs including the kidneys and salivary glands were similar to 68Ga-PSMA-11 imaging. [¹⁸F]-BF3-Cy3-ACUPA physiologic radiotracer accumulation and urinary/biliary excretion closely resembled the distribution of other published PSMA tracers including [¹⁸F]-JK-PSMA-7, [¹⁸F]-PSMA-1007, [¹⁸F]-DCFPyL, and [¹⁸F]-DCFBC. ¹⁹F-BF3-Cy3-ACUPA was retained in PSMA⁺ cancer in patients for at least 24 hours, allowing for intraoperative fluorescence assessment of the prostate and of the embedded prostate cancer without contrast reinjection. After 24 hours, the majority of contrast had decayed or cleared from the blood pool. Preoperative PET and fluorescence imaging findings were confirmed with final histopathology and multiphoton microscopy.

CONCLUSION

Our first-in-human results demonstrate that [¹⁸F]-BF3-Cy3-ACUPA is both safe and useful in humans. Larger trials with this PET tracer are expected to further define its capabilities and its clinical role in the management of PSMA⁺ tumors, especially in prostate cancer.

Ultraviolet spectrophotometric methods for the determination of the minor component presented in fixed-dose pharmaceutical combinations through the last two decades (2000–2020)

Background

The pharmaceutical industry and the National Regulatory Authorities are now focusing on the quantification of multi-component drugs for quality control testing.

Main body

Recently, the utilization of the ultraviolet spectrophotometric methods has become vital for the analytical studies for the routine analysis of different fixed-dose combination products either in the presence of a minor component in their combination or not. This article reviewed several published methods to those that have been applied to quantify some pharmaceutical combinations containing minor components through the last two decades.

Conclusion

The applied spectrophotometric methods are labor, time-saving, and also considered a cheap substitute for the overpriced high-performance liquid chromatographic technique.

Emerging Multi-Drug Eutectics: Opportunities and Challenges

Complexity and heterogeneous nature of most diseases have posed greater challenges in the modern healthcare system. Fixed-dose combination can offer an ideal way to improve patient compliance and higher therapeutic efficacy. However, biopharmaceutical issues associated with the drug combinations remain unaddressed. Multidrug eutectics (MDE) have demonstrated significant promise in improving the biopharmaceutical attributes with synergistic therapeutic action. Eutectic mixtures are the multicomponent solid forms that possess lesser melting point than the individual components at a fixed composition. Non-covalent linking of drug combinations as MDE is an innovative strategy with enhanced solubility, dissolution, and mechanical and potential therapeutic efficacy. This review provides a comprehensive overview of the design of MDE, rational selection of drugs, characterization tools, and their therapeutic potential. Besides, the futuristic perspective where MDE could make a significant impact on combination therapy is briefly outlined. Graphical Abstract.

Pharmaceutical impurity analysis by comprehensive two-dimensional temperature responsive × reversed phase liquid chromatography

In this study, the possibilities of temperature responsive × reversed phase liquid chromatography (TRLC × RPLC) are assessed in terms of pharmaceutical impurity analysis. Due to the increased peak capacity per unit time they offer, two-dimensional LC approaches are gaining relevance for the analysis of complex drug formulations. Because the latter depicts a larger predisposition for the occurrence of an increased number of impurities, current 1D-HPLC approaches often prove insufficient. Since many LC × LC methods are limited by modulation, solvent compatibility, orthogonality, and sensitivity issues, the combination of TRLC × RPLC is explored in this work for pharmaceutical impurity analysis. As this combination of a purely aqueous separation with RPLC allows for systematic and optimization-free refocusing in the second dimension, it opens possibilities for generic LC × LC requiring minimal to no method development, in this way overcoming a major perceived contemporary hurdle of LC × LC. The approach is demonstrated with a representative mixture of 17 solutes comprising 11 corticosteroids and 6 progestogens. Orthogonality and peak capacities were assessed on three RP core-shell column selectivities (Poroshell EC-C18, phenyl-hexyl and PFP). Although the TRLC × EC-C18 combination offered somewhat better orthogonality, the combination with the PFP column proved the best for the separation at hand. Depending on the composition of the mixture, the use of full, shifted, or segmented gradients allowed facile optimization of the separation. The developed platform allowed detection of the impurities at the 0.05% level compared to a selected main compound, while also opening up possibilities for analysis of formulations comprising two active ingredients.

Evaluation of assay and in-vitro dissolution profile of certain fixed-dose combination using green analytical method

OBJECTIVES

The pharmaceutical industry and the National Regulatory Authorities (NRAs) are now focusing on the dissolution of multi-component drugs for quality control testing and predicting in vivo results to further consolidation of the biowaiver concept. The mixed formulation of Ciprofloxacin hydrochloride (CIP) and Metronidazole (MET) have been used as a model for simultaneous determination and obtaining in vitro dissolution profiles by using green analysis method namely (UV-CWT_(Db4, _a=490)).

MATERIAL AND METHODS

The proposed method (UV-CWT_(Db4, _a=490)) includes UV detection combined with Continuous Wavelet Transform (CWT) with Daubechies family and the order of fourth at the scaling factor (a=490) has been used and validated for analyzing and obtaining the dissolution profiles of the fixed-dose combination (CIP-MET).

RESULTS

The proposed method (UV-CWT_(Db4, _a=490)) has been validated effectively in accordance with ICH rules, regarding linearity, specificity, rigor, and preciseness of the working range (3.0-16.0μg/mL) for both (CIP) and (MET), respectively. As well as figures of merit were concluded. The dissolution profiles of CIP-MET tablets were acquired by the proposed (UV-CWT _(Db4, _a=490)) and HPLC reported methods were conveniently compared using the indicators f₁ and f₂ ("difference" and "similarity") the results ensured that there were no statistically differences between the methods. In addition, the green assessment tool, namely analytical eco-scale, evaluated and compared the greenness of the suggested method (UV-CWT_(Db4, _a=490)) and HPLC reported one.

CONCLUSION

The suggested process (UV-CWT_(Db4, _a=490)) was considered as an excellent green, rapid, accurate, economical and minimum-steps method for simultaneously resolve and construct the dissolution curves of a fixed-dose combination drug (CIP-MET) in a short time and without the use of organic solvents, enabling significant labor and resource savings.

3D-Printed Solid Dispersion Drug Products

With the well-known advantages of additive manufacturing methods such as three-dimensional (3D) printing in drug delivery, it is disappointing that only one product has been successful in achieving regulatory approval in the past few years. Further research and development is required in this area to introduce more 3D printed products into the market. Our study investigates the potential of fixed dose combination solid dispersion drug products generated via 3D printing. Two model drugs-fluorescein sodium (FS) and 5-aminosalicyclic acid (5-ASA)-were impregnated onto a polyvinyl alcohol (PVA) filament, and the influence of solvent choice in optimal drug loading as well as other influences such as the physicochemical and mechanical properties of the resultant filaments were investigated prior to development of the resultant drug products. Key outcomes of this work included the improvement of filament drug loading by one- to threefold due to solvent choice on the basis of its polarity and the generation of a 3D-printed product confirmed to be a solid dispersion fixed dose combination with the two model drugs exhibiting favourable in vitro dissolution characteristics.

Photocurable Bioinks for the 3D Pharming of Combination Therapies

Combination therapies mediate drug synergy to improve treatment efficacy and convenience, leading to higher levels of compliance. However, there are challenges with their manufacturing as well as reduced flexibility in dosing options. This study reports on the design and characterization of a polypill fabricated through the combination of material jetting and binder jetting for the treatment of hypertension. The drugs lisinopril and spironolactone were loaded into hydrophilic hyaluronic acid and hydrophobic poly(ethylene glycol) (PEG) photocurable bioinks, respectively, and dispensed through a piezoelectric nozzle onto a blank preform tablet composed of two attachable compartments fabricated via binder jetting 3D printing. The bioinks were photopolymerized and their mechanical properties were assessed via Instron testing. Scanning electron microscopy (SEM) was performed to indicate morphological analysis. The polypill was ensembled and drug release analysis was performed. Droplet formation of bioinks loaded with hydrophilic and hydrophobic active pharmaceutical ingredients (APIs) was achieved and subsequently polymerized after a controlled dosage was dispensed onto preform tablet compartments. High-performance liquid chromatography (HPLC) analysis showed sustained release profiles for each of the loaded compounds. This study confirms the potential of material jetting in conjunction with binder jetting techniques (powder-bed 3D printing), for the production of combination therapy oral dosage forms involving both hydrophilic and hydrophobic drugs.

Systems Pharmacology: Defining the Interactions of Drug Combinations

The majority of diseases are associated with alterations in multiple molecular pathways and complex interactions at the cellular and organ levels. Single-target monotherapies therefore have intrinsic limitations with respect to their maximum therapeutic benefits. The potential of combination drug therapies has received interest for the treatment of many diseases and is well established in some areas, such as oncology. Combination drug treatments may allow us to identify synergistic drug effects, reduce adverse drug reactions, and address variability in disease characteristics between patients. Identification of combination therapies remains challenging. We discuss current state-of-the-art systems pharmacology approaches to enable rational identification of combination therapies. These approaches, which include characterization of mechanisms of disease and drug action at a systems level, can enable understanding of drug interactions at the molecular, cellular, physiological, and organismal levels. Such multiscale understanding can enable precision medicine by promoting the rational development of combination therapy at the level of individual patients for many diseases.

The Quality of Medicines Used in Children and Supplied by Private Pharmaceutical Wholesalers in Kinshasa, Democratic Republic of Congo: A Prospective Survey

Poor-quality medicines are a threat to public health in many low- and middle-income countries, and prospective surveys are needed to inform corrective actions. Therefore, we conducted a cross-sectional survey on a sample of products used for children and available in the private market in Kinshasa, Democratic Republic Congo: amoxicillin (AX) and artemether/lumefantrine (AL), powders for suspension, and paracetamol (PC) tablets 500 mg. Overall, 417 products were covertly purchased from 61 wholesalers. To obtain a representative sample, the products were weighted on their market shares and a subset of 239 samples was randomly extracted to undergo in-depth visual inspection locally, and they were chemically assessed at two accredited laboratories in Belgium. Samples were defined of “poor-quality” if they failed to comply with at least one specification of the International Pharmacopoeia (for AL) or United States Pharmacopoeia 37 (for AX and PC). Results are reported according to the Medicine Quality Assessment Reporting Guideline. The visual inspection detected nonconformities in the aspects of antimalarial powders for suspension, and poor-quality labels across all medicine types. According to chemical analysis, 27.2% samples were of poor quality and 59.5% of AL samples were underdosed in artemether. Poor quality was more frequent for locally manufactured antimalarials (83.3%, P = 0.021; 86.4%, P = 0.022) and PC (4.8%, P = 0.000). The poor quality of the surveyed products may decrease the treatment’s efficacy and favor the development of resistances to antimalarials. It is hoped that these findings may guide the corrective actions of the Democratic Republic of Congo Regulatory Authority, which was the main partner in the research.

Analysis of Fixed-Dose Combination Products Approved by the US Food and Drug Administration, 2010-2015: Implications for Designing a Regulatory Shortcut to New Drug Application

BACKGROUND

Fixed-dose combination (FDC) drugs have been an attractive product in pharmaceutical markets because of their unique advantages, but general guidance directing the clinical development of FDC drugs is not yet available in the US.

METHOD

All drug approval reports of FDC products approved by the US FDA from January 2010 to December 2015 were intensively analyzed to investigate the regulatory requirements of the US FDA.

RESULT

Through analyzing 63 approved FDCs out of 655 New Drug Application (NDA) approvals, it was found that completion of the full phases of clinical trials was not always required for approval by the FDA, which indicates that some phases of clinical studies can be possibly exempted, if justified.

CONCLUSION

The results imply that pharmaceutical companies can accelerate FDC development and enter the market earlier if scientific regulatory rationales are established.

Challenges in oral drug delivery of antiretrovirals and the innovative strategies to overcome them

Development of novel drug delivery systems (DDS) represents a promising opportunity to overcome the various bottlenecks associated with the chronic antiretroviral (ARV) therapy of the human immunodeficiency virus (HIV) infection. Oral drug delivery is the most convenient and simplest route of drug administration that involves the swallowing of a pharmaceutical compound with the intention of releasing it into the gastrointestinal tract. In oral delivery, drugs can be formulated in such a way that they are protected from digestive enzymes, acids, etc. and released in different regions of the small intestine and/or the colon. Not surprisingly, with the exception of the subcutaneous enfuvirtide, all the marketed ARVs are administered orally. However, conventional (marketed) and innovative (under investigation) oral delivery systems must overcome numerous challenges, including the acidic gastric environment, and the poor aqueous solubility and physicochemical instability of many of the approved ARVs. In addition, the mucus barrier can prevent penetration and subsequent absorption of the released drug, a phenomenon that leads to lower oral bioavailability and therapeutic concentration in plasma. Moreover, the frequent administration of the cocktail (ARVs are administered at least once a day) favors treatment interruption. To improve the oral performance of ARVs, the design and development of more efficient oral drug delivery systems are called for. The present review highlights various innovative research strategies adopted to overcome the limitations of the present treatment regimens and to enhance the efficacy of the oral ARV therapy in HIV.