Development of a simple paste for 3D printing of drug formulations containing a mesoporous material loaded with a poorly water-soluble drug

Poorly soluble drugs represent a substantial portion of emerging drug candidates, posing significant challenges for pharmaceutical formulators. One promising method to enhance the drug's dissolution rate and, consequently, bioavailability involves transforming them into an amorphous state within mesoporous materials. These materials can then be seamlessly integrated into personalized drug formulations using Additive Manufacturing (AM) techniques, most commonly via Fused Deposition Modeling. Another innovative approach within the realm of AM for mesoporous material-based formulations is semi-solid extrusion (SSE). This study showcases the feasibility of a straightforward yet groundbreaking hybrid 3D printing system employing SSE to incorporate drug-loaded mesoporous magnesium carbonate (MMC) into two different drug formulations, each designed for distinct administration routes. MMC was loaded with the poorly water-soluble drug ibuprofen via a solvent evaporation method and mixed with PEG 400 as a binder and lubricant, facilitating subsequent SSE. The formulation is non-aqueous, unlike most pastes which are used for SSE, and thus is beneficial for the incorporation of poorly water-soluble drugs. The 3D printing process yielded tablets for oral administration and suppositories for rectal administration, which were then analyzed for their dissolution behavior in biorelevant media. These investigations revealed enhancements in the dissolution kinetics of the amorphous drug-loaded MMC formulations. Furthermore, an impressive drug loading of 15.3 % w/w of the total formulation was achieved, marking the highest reported loading for SSE formulations incorporating mesoporous materials to stabilize drugs in their amorphous state by a wide margin. This simple formulation containing PEG 400 also showed advantages over other aqueous formulations for SSE in that the formulations did not exhibit weight loss or changes in size or form during the curing process post-printing. These results underscore the substantial potential of this innovative hybrid 3D printing system for the development of drug dosage forms, particularly for improving the release profile of poorly water-soluble drugs.

Combinatorial 3D printed dosage forms for a two-step and controlled drug release

Fused deposition modeling (FDM) and selective laser sintering (SLS) are two of the most employed additive manufacturing (AM) techniques within the pharmaceutical research field. Despite the numerous advantages of different AM methods, their respective drawbacks have yet to be fully addressed, and therefore combinatorial systems are starting to emerge. In the present study, hybrid systems comprising SLS inserts and a two-compartment FDM shell are developed to achieve controlled release of the model drug theophylline. Via the use of SLS a partial amorphization of the drug is demonstrated, which can be advantageous in the case of poorly soluble drugs, and it is shown that sintering parameters can regulate the dosage and release kinetics of the drug from the inserts. Furthermore, via different combinations of inserts within the FDM-printed shell, various drug release patterns, such as a two-step or prolonged release, can be achieved. The study serves as a proof of concept, highlighting the advantages of combining two AM techniques, both to overcome their respective shortcomings and to develop modular and highly tunable drug delivery devices.

In situ thermal image analysis of selective laser sintering for oral dosage form manufacturing

Additive Manufacturing (AM) is a fast-growing approach to produce personalized oral dosage forms. Even though some AM technologies are promising as alternative to conventional compounding with resulting dosage manipulation, they still suffer from a lack of quality control. Due to the high regulatory demands and standards applied to dosage forms in the case of dose accuracy and tablet properties such as friability, effective quality control is a key feature in promoting AM as a valid technology for patient-tailored medications. One of the AM techniques used is selective laser sintering, which allows for capturing the surface state layer-by-layer during the printing process. It provides the opportunity to apply non-destructive quality control based on image analysis extracting essential data at each layer of the sintering process. This work is devoted to establishing the value of data gathered via thermal image analysis for the subsequent quality control.

Selective laser sintering additive manufacturing of dosage forms: Effect of powder formulation and process parameters on the physical properties of printed tablets

Large batches of placebo and drug-loaded solid dosage forms were successfully fabricated using selective laser sintering (SLS) 3D printing in this study. The tablet batches were prepared using either copovidone (N-vinyl-2-pyrrolidone and vinyl acetate, PVP/VA) or polyvinyl alcohol (PVA) and activated carbon (AC) as radiation absorbent, which was added to improve the sintering of the polymer. The physical properties of the dosage forms were evaluated at different pigment concentrations (i.e., 0.5 and 1.0 wt%) and at different laser energy inputs. The mass, hardness, and friability of the tablets were found to be tunable and structures with greater mass and mechanical strength were obtained with increasing carbon concentration and energy input. Amorphization of the active pharmaceutical ingredient in the drug-loaded batches, containing 10 wt% naproxen and 1 wt% AC, was achieved in-situ during printing. Thus, amorphous solid dispersions were prepared in a single-step process and produced tablets with mass losses below 1 wt%. These findings show how the properties of dosage forms can be tuned by careful selection of the process parameters and the powder formulation. SLS 3D printing can therefore be considered to be an interesting and promising technique for the fabrication of personalized medicines.

[Molecular epidemiological analysis of SARS-CoV-2 genovariants in Moscow and Moscow region]

INTRODUCTION

SARS-CoV-2, a severe acute respiratory illness virus that emerged in China in late 2019, continues to spread rapidly around the world, accumulating mutations and thus causing serious concern. Five virus variants of concern are currently known: Alpha (lineage B.1.1.7), Beta (lineage B.1.351), Gamma (lineage P.1), Delta (lineage B.1.617.2), and Omicron (lineage B.1.1.529). In this study, we conducted a molecular epidemiological analysis of the most prevalent genovariants in Moscow and the region. The aim of the study is to estimate the distribution of various variants of SARS-CoV-2 in Moscow city and the Moscow Region.

MATERIALS AND METHODS

227 SARS-CoV-2 sequences were used for analysis. Isolation of the SARS-CoV-2 virus was performed on Vero E6 cell culture. Sequencing was performed by the Sanger method. Bioinformatic analysis was carried out using software packages: MAFFT, IQ-TREE v1.6.12, jModelTest 2.1.7, Nextstrain, Auspice v2.34.

RESULTS

As a result of phylogenetic analysis, we have identified the main variants of the virus circulating in Russia that have been of concern throughout the existence of the pandemic, namely: variant B.1.1.7, which accounted for 30% (9/30), AY.122, which accounted for 16.7% (5/30), BA.1.1 with 20% (6/30) and B.1.1 with 33.3% (10/30). When examining Moscow samples for the presence of mutations in SARS-CoV-2 structural proteins of different genovariants, a significant percentage of the most common substitutions was recorded: S protein D614G (86.7%), P681H/R (63.3%), E protein T9I (20.0%); M protein I82T (30.0%), D3G (20.0%), Q19E (20.0%) and finally N protein R203K/M (90.0%), G204R/P (73.3 %).

CONCLUSION

The study of the frequency and impact of mutations, as well as the analysis of the predominant variants of the virus are important for the development and improvement of vaccines for the prevention of COVID-19. Therefore, ongoing molecular epidemiological studies are needed, as these data provide important information about changes in the genome of circulating SARS-CoV-2 variants.

[Detection of meningococcal meningitis epidemics in Africa: a new recommendation]

In sub-Saharan Africa, the control of meningococcal meningitis epidemics relies on early epidemic detection and mass vaccination. However, experience shows that interventions are often initiated too late to have a significant impact on the epidemic. A new recommendation drafted by participants of a consensus meeting proposes an alert threshold and an epidemic threshold based on the weekly number or incidence of meningitis cases, according to the population size and the epidemic risk, resulting in indicators with high sensitivity and specificity for the detection of an emerging epidemic. Meningitis outbreak investigations must include an assessment of the quality of epidemiologic surveillance. The new recommendation is published in English and French in the Weekly Epidemiologic Record [12]. The success of this consensus meeting shows the value of integrating results from surveillance, field experience and operational research for designing new health strategies.

Immunogenicity of two efficacious outer membrane protein-based serogroup B meningococcal vaccines among young adults in Iceland

Serum bactericidal activity (SBA) and ELISA antibody levels elicited by two efficacious serogroup B meningococcal vaccines were measured in a controlled trial involving 408 15- to 20-year-olds. Subjects were given two doses at a 6-week interval of a serogroup B or control vaccine. Response was defined as > or = 4-fold rise in antibody level. After two doses of the Finlay Institute (Havana) vaccine at 12 months, the proportions of SBA and ELISA responders were not different from those of the control group (15% and 17% [vaccine] vs. 13% and 9% [control], P > .05). After two doses of the National Institute of Public Health (Oslo) vaccine, there were more SBA and ELISA responders than in the control group (47% and 34% [vaccine] vs. 10% and 1% [control]) or the Finlay Institute vaccine group (P < .05 for both). SBA and ELISA may be insensitive correlates for protective efficacy for some outer membrane protein-based serogroup B meningococcal vaccines.

Meningococcal disease: public health burden and control

Meningococcal disease which is increasing globally is still associated with a high mortality and persistent neurological defects, particularly among infants and young children. Sporadic meningococcal meningitis occurs throughout the world, with seasonal variations, and accounts for 10-40% of endemic bacterial meningitis. Epidemic meningitis occurs in any part of the world but the largest and most frequently recurring epidemics have been in the semi-arid area of sub-Saharan Africa where the current pandemic is associated with attack rates exceeding 500 per 100,000 population and thousands of deaths. In the Americas and Europe serogroup B is the predominant agent causing systemic disease, followed in frequency by serogroup C. Serogroup A meningococcus was historically the main cause of epidemic meningococcal disease globally and still predominates in Africa and Asia. A range of internal and external factors predispose for epidemics such as strain virulence, carriers, humoral immunity, co-infections, low humidity and drought, population movements and crowding. To respond to the current situation and the expected spread of the disease, WHO, in collaboration with its Member States and various governmental and non-governmental agencies, has developed a sustainable plan of action for preparedness and control of meningitis.

Multicentre evaluation of a direct coagglutination test for group A streptococci

A coagglutination test for detection of group A streptococci in throat samples was evaluated in a multicentre study and found to be about 95% sensitive when applied to swabs taken from symptomatic patients which yielded more than 100 colonies per plate on culture. The sensitivity of the test dropped significantly when it was applied to swabs giving fewer than 100 colonies on culture. The specificity of the test was high regardless of colony count on conventional media.

WHO programme for the control of hospital infections

The results of the WHO cooperative study show that hospital-acquired infections (HAI) should be considered as an important problem in both developed and developing countries. The Hospital Infection Prevalence Survey carried out in 14 countries representing four regions revealed the mean prevalence rate of 8.7% HAI with the highest frequency in intensive care, acute surgical and orthopedic units. The most common HAI were of surgical wounds (25.1% of all infections), followed by urinary tract infections (22.0%) and lower respiratory infection (20.5%). Predominant organisms causing the infection were Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.

Streptococcal diseases worldwide: present status and prospects

Infections caused by streptococci pathogenic for man are some of the most common bacterial diseases in temperate zones and occur very frequently in tropical and subtropical countries. The highest morbidity occurs from infections caused by group A streptococci; these infections can lead to rheumatic fever and acute glomerulonephritis. The incidence of rheumatic fever and the prevalence of rheumatic heart disease are several times higher in tropical countries than temperate countries.Recent developments in fundamental and applied research are throwing light on various aspects of the problem, e.g., the rapid (non-culture) identification of group A streptococcal infection. Analyses of the chemical structure of the M-protein molecule of group A streptococcus and of the biological properties of the epitopes of the M-protein have provided encouraging results. Furthermore, synthetic analogues of the protective immunodominant polypeptides of the M-protein have been prepared. The prospect of a streptococcal vaccine for preventing group A streptococcal diseases is thus more realistic.The control of infections caused by group B streptococci is important for the health of neonates. The identification of the chemical structure of the major group B streptococcal types may lead to development of a vaccine in the future. An alternative approach would entail the use of anti-group-B immunoglobulins, but a number of questions have to be answered before the new control measures can be introduced. The streptococci causing bacterial pneumonia, subacute bacterial endocarditis and possibly dental caries have been widely studied and promising advances have been made towards the introduction of better control of the diseases caused by these pathogens.