Long-acting injectable formulations of antipsychotic drugs for the treatment of schizophrenia

Novel pH-Responsive Structural Rearrangement of Myristic Acid-Conjugated Quetiapine Nanosuspension for Enhanced Long-Acting Delivery Performance

Quetiapine myristate (QM), an ester-bonded lipophilic prodrug of quetiapine (QTP), is synthesized and converted into an amphiphilic structure in acidic pH to trigger a novel self-assembled QM nanosuspension (QMN). Following injection, this QMN rearranges within physiological pH to form nanoaggregates in structure, resulting in enhanced physicochemical properties and in vivo therapeutic performance without an initial burst release. The 200-nm-sized QMN exhibits less invasive injection, higher drug content, and better storage stability profile than conventional poly(lactide-co-glycolide) (PLGA) nanosuspensions containing QTP or QM. Following a single intramuscular injection to beagle dogs (35 mg kg-1 QTP), QMN undergoes pH-responsive nanoaggregation to form the lipophilic prodrug, providing esterase-oriented sustained release for five weeks compared with the two-week period of PLGA nanosuspensions. Notably, QMN exhibits improved in vivo pharmacokinetic performance with long-acting delivery while minimizing issues associated with polymeric PLGA formulations, including the initial massive burst release, cellular toxicity, and adverse side effects. These results support the further development of QMN as a novel long-acting injectable to improve patient compliance and dosing frequency.

A Systematic Investigation of Process Parameters for Small-Volume Aqueous Suspension Production by the Use of Focused Ultrasonication

Aqueous suspensions containing crystalline drug in the sub-micron range is a favorable platform for long-acting injectables where particle size can be used to obtain a desired plasma-concentration profile. Stabilizers are added to the suspensions and screened extensively to define the optimal formulation composition. In the initial formulation screening the amount of drug compound can be limited, necessitating milling methods for small-volume screening predictable for scale-up. Hence, adaptive focused ultrasound was investigated as a potential milling method for rapid small-volume suspensions by identifying the critical process parameters during preparation. Suspensions containing drug compounds with different mechanical properties and thereby grindability, i.e., cinnarizine, haloperidol, and indomethacin with brittle, elastic, and plastic properties, respectively, were investigated to gain an understanding of the manufacturing with adaptive focused acoustics as well as comparison to already established milling techniques. Using a DoE-design, peak incident power was identified as the most crucial process parameter impacting the milling process for all three compounds. It was possible to decrease the sizes of drug particles to micron range after one minute of focused ultrasound exposure which was superior compared to other milling techniques (e.g., non-focused ultrasound exposure). The addition of milling beads decreased the drug particle sizes even further, thus to a lower degree than other already established milling techniques such as milling by dual centrifugation. This study thereby demonstrated that adaptive focused ultrasonication was a promising method for rapid homogenization and particle size reduction to micron range for different compounds varying in grindability without altering the crystalline structure.

Relationships between medications used in a mental health hospital and types of medication errors: A cross-sectional study over an 8-year period

BACKGROUND

Particularities in psychiatry care can increase the risk of medication errors (MEs).

OBJECTIVE

To analyze the MEs that occurred in a psychiatric hospital and to quantify relationships between the use of certain types of medication and the type of MEs.

METHODS

We conducted a retrospective register based cross-sectional study in a French psychiatric hospital (2014-2021). All MEs were analyzed using ALARM method to identify type, stage of occurring and interception (defenses), consequences, drug involved and root causes. The prevalence-odds ratio (POR) was calculated to estimate relationships between five selected medication situations (long-acting injectable antipsychotics (LAIA), oral liquid dosage forms in a multiple-unit-container (OLDS-MC), psychotropic drugs (PD), controlled medicines (CM) or high-alert drugs) and the type of MEs occurred.

RESULTS

Among the 609 MEs reported, wrong dose (32.2%), wrong drug (30.3%), omission (14.2%) and wrong patient (12.9%) were frequently observed. The ME occurrence stage were prescribing (55.3%) and administration (30.2%). Medication order review intercepted 77.9% of MEs. CM or LAIA increased the risk of medication omission (POR: 3.9, 95%CI: 1.8-8.4 and 2.5, 95%CI; 1.2-5.1, respectively) while the use of high-alert medications decreased it (0.2, 95%CI: 0.1-0.8). OLDS-MC and PD were more likely to be administered to the wrong patient (6.1, 95%CI: 3.3-11.4 and 16.1, 95%CI: 7.2-35.8). LAIA were associated with an increased risk of wrong dose (3.4, 95%CI: 1.8-6.3). Actual errors risk was lower with high-alert drugs (0.5, 95%CI: 0.3-09), but higher with CM (3.5, 95%CI: 1.5-8.0), OLDS-MC (2.1, 95%CI: 1.2-3.8) and PD (2.5, 95%CI: 1.8-3.5). Patients exposed to high-alert drugs were likely to have a serious error (3.5, 95%CI: 1.2-10.4).

CONCLUSIONS

This study sheds an innovative approach to analyze MEs by demonstrating that certain medication situations were more likely to lead to certain types of error. This enables the most appropriate prevention barriers to be put in place to intercept ME.

Differences in schizophrenia treatments by race and ethnicity-analysis of electronic health records

Racial disparities in prescriptions of anti-psychotics have been highlighted before. However, (i) the evidence on other medications, including anti-depressant or mood stabilizing medications is lacking, and (ii) the role of potentially confounding factors and (iii) specificity of such disparities to schizophrenia (SCZ), are still unknown. We used electronic health records (EHRs) from 224,212 adults to estimate the odds ratios of receiving a prescription for different nervous system medications among patients with SCZ of different race/ethnicity, and analogous linear models to investigate differences in prescribed medication doses. To verify specificity of the observed patterns to SCZ, we conducted analogous analyses in depression and bipolar disorder (BD) patients. We found that Black/African American (AA) and Hispanic patients with SCZ were more likely to be prescribed haloperidol (Black/AA: OR = 1.52 (1.33-1.74); Hispanic: OR = 1.32 (1.12-1.55)) or risperidone (Black/AA: OR = 1.27 (1.11-1.45); Hispanic: OR = 1.40 (1.19-1.64)), but less likely to be prescribed clozapine (Black/AA: OR = 0.40 (0.33-0.49); Hispanic: OR = 0.45 (0.35-0.58)), compared to white patients. There were no race/ethnicity-related differences in the prescribed medication doses. These patterns were not specific to SCZ: Asian, Hispanic and Black/AA patients with BD or depression were more likely to be prescribed anti-psychotics, but less likely to be prescribed antidepressants or mood-stabilizers. In conclusion, we found racial/ethnic disparities in the medications prescribed to patients with SCZ and other psychiatric conditions. We discuss the potential implications for the quality of care for patients of diverse races/ethnicities.

Combination of Two Long-Acting Antipsychotics in Schizophrenia Spectrum Disorders: A Systematic Review

BACKGROUND

Up to 34% of patients with schizophrenia are resistant to several treatment trials. Lack of continuous and adequate treatment is associated with relapse, rehospitalization, a lower effect of antipsychotic therapy, and higher risk of side effects. Long-acting injectables antipsychotics (LAI APs) enhance compliance and improve clinical outcomes and quality of life in patients with schizophrenia, and thus it may be advisable to administer two LAI APs at the same time in cases of treatment-resistant schizophrenia. The purpose of this review is to summarize the available literature regarding the combined use of two LAI APs in patients with schizophrenia or other psychotic spectrum disorders.

METHODS

An extensive literature search for relevant articles regarding any combination of two long-acting injectable antipsychotics has been performed from inception up to 9 February 2024, on PubMed, Scopus and APA PsycInfo, according to the PRISMA statement. Only studies reporting combination of two LAI APs and its clinical outcome in patients with schizophrenia and related disorders were selected.

RESULTS

After the selection process, nine case reports, four case series and two observational retrospective studies were included in the final analysis. All patients treated with dual LAI APs reported a good response, and no new or unexpected adverse effects due to the combination of two LAIs were reported. Different drug combinations were used, and the most frequent association resulted in aripiprazole monohydrate + paliperidone palmitate once monthly (32 times).

CONCLUSIONS

Our review highlights that the treatment regimen with two concurrent LAI APs is already widely used in clinical practice and is recognized as providing a promising, effective, and relatively safe therapeutic strategy for treating the schizophrenia spectrum disorders.

Symptomatic remission and recovery in major psychosis: Is there a role for BDNF? A secondary analysis of the LABSP cohort data

Remission, relapse prevention, and clinical recovery are crucial areas of interest in schizophrenia (SCZ) research. Although SCZ is a chronic disorder with poor overall outcomes, years of research demonstrated that recovery is possible. There are considerable data linking brain-derived neurotrophic factor (BDNF) to SCZ, however, evidence on the role of BDNF in remission in SCZ is scarce. This secondary analysis of the Longitudinal Assessment of BDNF in Sardinian patients (LABSP) data aimed to investigate the relationship between serum BDNF levels and symptomatic remission, simultaneous clinical and functional remission, and recovery in patients with SCZ. A total of 105 patients with SCZ or schizoaffective disorder were recruited for a longitudinal assessment of BDNF levels over 24 months. Longitudinal data were analyzed using mixed-effects linear regression models. The study found significant associations between use of long acting injectables (χ2 = 7.075, df = 1, p = 0.008), baseline serum BDNF levels (U = 701, z = -2.543, p = 0.011), and "childhood" (U = 475, z = -2.124, p = 0.034) and "general" (U = 55, z = -2.014, p = 0.044) subscales of the Premorbid Adjustment Scale (PAS) with patients maintaining remission and recovery. The diagnosis of SCZ was significantly associated with lower BDNF levels for patients with simultaneous clinical and functional remission (Z = 2.035, p = 0.0419) and recovery (Z = 2.009, p = 0.0445) compared to those without. There were no significant associations between remission in the entire sample and longitudinal serum BDNF levels or genetic variants within the BDNF gene. These findings provide further insight into the complex relationship between BDNF and SCZ.

Optimization of Lurasidone HCl-Loaded PLGA Nanoparticles for Intramuscular Delivery: Enhanced Bioavailability, Reduced Dosing Frequency, Pharmacokinetics, and Therapeutic Outcomes

This study aimed to develop a nanoparticle drug delivery system using poly (lactic-co-glycolic acid) (PLGA) for enhancing the therapeutic efficacy of lurasidone hydrochloride (LH) in treatment of schizophrenia through intramuscular injection. LH-loaded PLGA nanoparticles (LH-PNPs) were prepared using the nanoprecipitation technique and their physicochemical characteristics were assessed. Particle size (PS), zeta potential, morphology, % encapsulation efficiency, % drug loading, drug content, and solid-state properties were analyzed. Stability, in vitro release, and in vivo pharmacokinetic studies were conducted to evaluate the therapeutic efficacy of the developed LH-PNPs. The optimized batch of LH-PNPs exhibited a narrow and uniform PS distribution before and after lyophilization, with sizes of 112.7 ± 1.8 nm and 115.0 ± 1.3 nm, respectively, and a low polydispersity index. The PNPs showed high drug entrapment efficiency, drug loading, and drug content uniformity. Solid-state characterization indicated good stability and compatibility, with a nonamorphous state. The drug release profile demonstrated sustained release behavior. Intramuscular administration of LH-PNPs in rats resulted in a significantly prolonged mean residence time compared with the drug suspension. These findings highlight that intramuscular delivery of the LH-PNP formulation is a promising approach for enhancing the therapeutic efficacy of LH in treatment of schizophrenia.

Impact of long-acting injectable antipsychotics vs. oral medication on relapses of patients with psychosis and bipolar disorder

Relapse associated with multiple hospital readmissions of patients with chronic and severe mental disorders, such as psychosis and bipolar disorder, is frequently associated with non-adherence to treatment. The primary aim of the study was to compare the effectiveness of long-acting injectable (LAI) treatment, vs. oral medication in reducing readmissions of patients with psychotic or bipolar disorder in a community sample of 164 patients with psychosis and 29 patients with bipolar disorder (n = 193), with poor adherence to oral medication. The mean follow up period was 5.6 years and the number of readmissions were compared for an equal-length period of oral treatment preceding the onset of LAI administration. We observed a significant decrease of 45.2 % in total hospital readmissions after receiving LAIs treatment. The effect was significant both for patients with a pre-LAI treatment history of predominantly voluntary hospitalizations and with predominantly involuntary admissions. In addition, we observed equal effectiveness of first- vs. second-generation LAIs in reducing total hospital readmissions regardless of type of pre-treatment admission history (voluntary vs. involuntary). LAIs appear to be effective in reducing both voluntary and involuntary hospital readmissions in patients with psychosis and bipolar disorder with a history of poor adherence to treatment.

Long-Acting Injectable Antipsychotics-A Review on Formulation and In Vitro Dissolution

Long-acting injectable (LAI) neuroleptics constitute an effective therapeutical alternative for individuals suffering from persistent mental illness. These injectable pharmaceuticals help patients manage their condition better and improve long-term outcomes by preventing relapses and improving compliance. This review aims to analyse the current formulation aspects of LAI neuroleptics, with particular emphasis on analysis of drug release profiles as a critical test to guarantee drug quality and relevant therapeutical activity. While there is no officially approved procedure for depot parenteral drug formulations, various dissolution tests which were developed by LAI manufacturers are described. In vitro dissolution tests also possess a critical function in the estimation of the in vivo performance of a drug formulation. For that reason, thorough inspection of the in vitro-in vivo correlation (IVIVC) is also discussed.

Roles of Fatty Acid Chain Length and Enzyme-Oriented Drug Controlled Release from pH-Triggering Self-Assembled Fatty Acid Conjugated Quetiapine Nanosuspensions

Background

Quetiapine (QTP) is a first-line antipsychotic drug, but its therapeutic druggability and patient adherence were limited due to high oral dose strength, low bioavailability and physicochemical/biopharmaceutical issues.

Purpose

To investigate the roles of fatty acid chain length and enzyme-oriented QTP controlled release from pH-triggering self-assembled fatty acid conjugated QTP nanosuspensions (NSPs).

Methods

QTP was conjugated with different chain length fatty acids (C10-decanoic acid, C14-myristic acid, C18-stearic acid) to obtain QTP-fatty acid conjugates (QFCs: QD, QM, QS) by exploiting 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/4-dimethylaminopyridine (EDC/DMAP) conjugation chemistry. Then, the solubility, partitioning coefficient (log P), cell viability and cleavage kinetics of QFCs were evaluated. The pH-triggering self-assembled behaviors of QFCs to form QTP-fatty acid NSPs (QDN, QMN, QSN) by varying pH, QFC concentration and proton-to-QTP ratios were characterized. The morphological images, critical micelle concentration (CMC), physicochemical properties and enzyme-oriented QTP controlled release of NSPs were examined.

Results

Three QFCs were synthesized with different chain length fatty acids from QTP after desalting fumarate from QTP fumarate. The pH, QFC concentration and proton-to-quetiapine molar ratio could influence physicochemical properties and nanonization behaviors of QFCs. All three QFCs showed no effect on the viability of myoblast cells. The pH-triggering self-assembly of amphiphilic QFCs to form nanoparticles (NPs) occurred as the amine moiety of QTP was readily ionized in a strongly acidic environment (pH 1.2). Interestingly, the longer the fatty acid chain length, the lower water solubility, the higher log P (lipophilicity) and the smaller NP particle size were observed. The conversion rate of QFCs to liberate QTP by esterase in human plasma and liver S9 fractions was also inversely proportional to the fatty acid carbon chain length. Interestingly, the freeze-dried QMN showed the esterase-oriented controlled release of QTP over one month, unlike the initial burst release of QDN or the slowly delayed release pattern of QSN.

Conclusion

A new pH-triggering self-assembled nanonization platform was developed using different chain length fatty acid conjugated QTP in low pH environment. By varying fatty acid chain length, the enzyme-oriented QTP controlled release dosage form was challenged to enhance the therapeutic effectiveness of QTP.

Advanced drug delivery and therapeutic strategies for tuberculosis treatment

Tuberculosis (TB) remains a significant global health challenge, necessitating innovative approaches for effective treatment. Conventional TB therapy encounters several limitations, including extended treatment duration, drug resistance, patient noncompliance, poor bioavailability, and suboptimal targeting. Advanced drug delivery strategies have emerged as a promising approach to address these challenges. They have the potential to enhance therapeutic outcomes and improve TB patient compliance by providing benefits such as multiple drug encapsulation, sustained release, targeted delivery, reduced dosing frequency, and minimal side effects. This review examines the current landscape of drug delivery strategies for effective TB management, specifically highlighting lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, emulsion-based systems, carbon nanotubes, graphene, and hydrogels as promising approaches. Furthermore, emerging therapeutic strategies like targeted therapy, long-acting therapeutics, extrapulmonary therapy, phototherapy, and immunotherapy are emphasized. The review also discusses the future trajectory and challenges of developing drug delivery systems for TB. In conclusion, nanomedicine has made substantial progress in addressing the challenges posed by conventional TB drugs. Moreover, by harnessing the unique targeting abilities, extended duration of action, and specificity of advanced therapeutics, innovative solutions are offered that have the potential to revolutionize TB therapy, thereby enhancing treatment outcomes and patient compliance.

Wet bead milling by dual centrifugation - An approach to obtain reproducible and differentiable suspensions

Aqueous nano- and microsuspensions containing poorly water-soluble, crystalline drug particles have in the recent years sparked an interest for the preparation of long-acting injectables (LAIs), which increase patient compliance for patients treated for long-term or chronic conditions. Nano- and microsuspensions are often prepared by top-down methods, such as wet bead milling, with the addition of stabilizers in the dispersion media, such as surfactants, which influence the particle sizes and physical stability of the suspension. To improve the efficacy of formulation screening for nano- and microsuspensions, dual centrifugation was utilized in this study whereby 40 samples could be manufactured simultaneously to support the formulation definition. Hence, the type and concentration of stabilizer as well as bead size and milling speed was investigated throughout the presented study, but also the ability of the method to produce consistent data was investigated. The obtained results demonstrated that the particle profile obtained after milling was very consistent from run to run and so was the observed stability data, i.e., running n = 1 experiment per combination could clearly be justified as a predictable approach for the formulation screening. The data also showed that the stabilizer, as well as its concentration highly influenced the physical stability of suspensions containing both the two investigated model compounds, i.e., both cinnarizine and indomethacin, where the biggest increase in particle sizes was observed within the first week. For short-term studies, polysorbate 20 was found to be a suitable stabilizer for suspensions of cinnarizine, whereas sodium dodecyl sulphate was more suitable for indomethacin suspensions immediately after the milling even with 1% (w/v) stabilizer solution, but not sufficient for short-term stability due to an insufficient stabilizer concentration. Smaller particles sizes could be achieved by milling the suspensions with the smallest bead sizes and at the highest speed of 1500 rpm without disrupting the crystal structure of the active pharmaceutical ingredient (API), which was confirmed by X-ray Powder Diffraction.

Recent advances in lipid-based long-acting injectable depot formulations

Long-acting injectable (LAIs) delivery systems sustain the drug therapeutic action in the body, resulting in reduced dosage regimen, toxicity, and improved patient compliance. Lipid-based depots are biocompatible, provide extended drug release, and improve drug stability, making them suitable for systemic and localized treatment of various chronic ailments, including psychosis, diabetes, hormonal disorders, arthritis, ocular diseases, and cancer. These depots include oil solutions, suspensions, oleogels, liquid crystalline systems, liposomes, solid lipid nanoparticles, nanostructured lipid carriers, phospholipid phase separation gel, vesicular phospholipid gel etc. This review summarizes recent advancements in lipid-based LAIs for delivering small and macromolecules, and their potential in managing chronic diseases. It also provides an overview of the lipid depots available in market or clinical phase, as well as patents for lipid-based LAIs. Furthermore, this review critically discusses the current scenario of using in vitro release methods to establish IVIVC and highlights the challenges involved in developing lipid-based LAIs.

Creation of a ready-to-use brexpiprazole suspension and the inflammation-mediated pharmacokinetics by intramuscular administration

Brexpiprazole (BPZ), which is approved for the treatment of schizophrenia and major depressive disorder, has the potential to meet diverse clinical needs. This study aimed to develop a long-acting injectable (LAI) formulation of BPZ that could provide sustained therapeutic benefits. A library of BPZ prodrugs was screened through esterification, and BPZ laurate (BPZL) was identified as an optimal candidate. To achieve stable aqueous suspensions, a pressure- and nozzle size-controlled microfluidization homogenizer was utilized. The pharmacokinetics (PK) profiles, considering dose and particle size modulation, were investigated following a single intramuscular injection in beagles and rats. BPZL treatment resulted in sustained plasma concentrations above the median effective concentration (EC₅₀) for 2∼3 weeks, without exhibiting an initial burst release. Histological examination of foreign body reaction (FBR) in rats revealed the morphological evolution of an inflammation-mediated drug depot, confirming the sustained release mechanism of BPZL. These findings provide strong support for the further development of a ready-to-use LAI suspension of BPZL, which could potentially enhance treatment outcomes, improve patient adherence, and address the clinical challenges associated with long-term regimens of schizophrenia spectrum disorders (SSD).

Long Acting Ionically Paired Pamoate-based Suspension of Lurasidone: An exploration of Size Effects on in vitro Dissolution and in vivo Pharmacokinetic Behaviors

Latuda® is an oral tablet approved by the US Food and Drug Administration (FDA) for the treatment of schizophrenia. However, the clinical efficacy of Latuda® is compromised by patient noncompliance due to frequent daily administration, especially for patients experiencing severe schizophrenia, whose medication is often needed for several months to years. Hence, developing a long-acting injectable formulation of lurasidone is urgently needed. Herein, a poorly water-soluble lurasidone pamoate (LP) salt was synthesized via the facile ion pair-based salt formation technology. The solubility of LP was decreased by 233 folds compared with that of lurasidone hydrochloride (LH). Furthermore, suspensions of LH and LP with three different particle sizes, including 400 nm small-sized nanocrystals (SNCs), 4 μm medium-sized microcrystals (MMCs), and 15 μm large-sized microcrystals (LMCs) were prepared and characterized by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The in vitro release results showed that particle sizes had great effects on the sustained release of LH, where large-sized particles exhibited superior sustained release than the smaller ones. Besides, LP suspensions exhibited better sustained release than LH suspensions at the same size scale. Moreover, the pharmacokinetics showed that LP LMCs produced an extended in vivo intramuscularly injectable profile for up to 45 days, which was 10 days longer than that of the LH LMCs. Our findings demonstrated that particle size had appreciable impacts on drug sustained release and provided valuable knowledge for the rational design of optimized micronized suspensions for long-acting injectables.

An ultralong-acting tenofovir ProTide nanoformulation achieves monthslong HBV suppression

Treatment of chronic hepatitis B virus (HBV) requires lifelong daily therapy. However, suboptimal adherence to the existing daily therapy has led to the need for ultralong-acting antivirals. A lipophilic and hydrophobic ProTide was made by replacing the alanyl isopropyl ester present in tenofovir alafenamide (TAF) with a docosyl phenyl alanyl ester, now referred to as M1TFV. NM1TFV and nanoformulated TAF (NTAF) nanocrystals were formulated by high-pressure homogenization. A single intramuscular injection of NM1TFV, but not NTAF, delivered at a dose of TFV equivalents (168 milligrams per kilogram) demonstrated monthslong antiviral activities in both HBV-transgenic and human hepatocyte transplanted TK-NOG mice. The suppression of HBV DNA in blood was maintained for 3 months. Laboratory experiments on HBV-transfected HepG2.2.15 cells affirmed the animal results and the critical role of docosanol in the sustained NM1TFV antiviral responses. These results provide clear "proof of concept" toward an emerging therapeutic paradigm for the treatment and prevention of HBV infection.

Effect of 3-monthly paliperidone palmitate on hospitalisation in a naturalistic schizophrenia cohort - A five-year mirror image study

PURPOSE/BACKGROUND

Currently the longest-acting antipsychotic formulation widespread clinical use is paliperidone 3-monthly injection (PP3M). While its efficacy has been shown in rigorous trials, there are few data relating to its effect on hospitalisation in normal clinical practice.

METHODS/PROCEDURES

This was a mirror-image study (3 years before; 2 years after) of hospitalisations before and after beginning paliperidone 1-monthly (PP1M) and switching to 3-monthly within 18 months. All consecutive patients prescribed paliperidone long-acting injections with its licence (F20 schizophrenia diagnosis; 18-65 years) were included. The setting was an urban, specialist mental health organisation In London, UK.

FINDINGS/RESULTS

In total 378 patients were initiated on PP3M during the study period. After applying inclusion criteria, 76 patients were retained and followed-up for 2 years. Mean duration of PP1M use before starting 3-monthly injections was 6 months (range 3-18 months). Of the 76 patients initiated, 13 patients discontinued PP3M within 2 years of starting PP1M or were lost to follow-up. Mean hospitalisations per patient per year fell from 0.55 (SD 0.46) before paliperidone to 0.05 (SD 0.19) after initiation (p < 0.001). Only 5 of 76 PP1M/PP3M participants were hospitalised during the 2-year follow up. The mean number of bed days per year before paliperidone initiation was 32.2 (SD 44.3) and after paliperidone initiation it was 23.0 (SD 53.2) (p = 0.004). Almost all of the bed days after initiation were associated with the index admission during which PP1M was started.

IMPLICATIONS/CONCLUSIONS

In patients stabilised on PP1M and switched to PP3M in normal clinical practice, rehospitalisation is very uncommon and much reduced compared with previous treatments.

Modulation of the clinically accessible gelation time using glucono-d-lactone and pyridoxal 5'-phosphate for long-acting alginate in situ forming gel injectable

The purpose of this study was to design alginate in situ forming gel (ISFG) injectable with clinically acceptable gelation time and controlled release of hydrophobic drug. Milled or unmilled paliperidone palmitate (PPP) was used. The gelation time was controlled by varying the ratios of glucono-d-lactone (GDL) and pyridoxal 5'-phosphate (PLP) in prefilled alginate solution mixtures (ASMs) containing PPP, CaCO₃, GDL and PLP for clinically acceptable injectability. However, the gelation time was varied by the alginate type (M/G ratio), storage condition, and drug solubilizers. This ISFG exhibited 32.15 kPa of the maximal compressive stress without causing pain and stiffness. The ISFG containing conically milled PPP released PPP in a controlled manner without exhibiting any initial burst release for 4 weeks. The current alginate ISFG injectable using new combination of PLP and GDL could be used to deliver long-acting injectable drugs.

Predictors of long-acting injectable antipsychotic prescription at discharge in patients with schizophrenia and other psychotic disorders

Long-acting injectable antipsychotics (LAIs) increase drug compliance and offer a reliable treatment option with stable pharmacokinetics. The aim of our study is to examine the rate and predictors of LAIs' prescription at discharge in inpatients with schizophrenia and other psychotic disorders. This retrospective study included 400 inpatients. Sociodemographic and clinical characteristics of the patients, the treatments applied in the past and prescribed at discharge were obtained from the hospitalization files. We compared these characteristics of those who were given LAI treatment at discharge to the patients who were given oral treatments. Thirty-nine percent of the patients were prescribed a LAI at discharge. Duration of illness was longer, and number of previous hospitalizations was higher in the LAI group. Nonadherence to the antipsychotics before the hospitalization, the previous history of LAI use, lack of insight at the admission and no previous antidepressant use were found as independent contributors to LAI prescription as the treatment of discharge in logistic regression analysis. Our study showed that LAIs are used at a high rate in our clinic; however, they are still initiated at a later stage, mostly in chronic patients with a lack of insight and compliance at admission.

Recent Progress in Drug Release Testing Methods of Biopolymeric Particulate System

Biopolymeric microparticles have been widely used for long-term release formulations of short half-life chemicals or synthetic peptides. Characterization of the drug release from microparticles is important to ensure product quality and desired pharmacological effect. However, there is no official method for long-term release parenteral dosage forms. Much work has been done to develop methods for in vitro drug release testing, generally grouped into three major categories: sample and separate, dialysis membrane, and continuous flow (flow-through cell) methods. In vitro drug release testing also plays an important role in providing insight into the in vivo performance of a product. In vitro release test with in vivo relevance can reduce the cost of conducting in vivo studies and accelerate drug product development. Therefore, investigation of the in vitro-in vivo correlation (IVIVC) is increasingly becoming an essential part of particulate formulation development. This review summarizes the principles of the in vitro release testing methods of biopolymeric particulate system with the recent research articles and discusses their characteristics including IVIVC, accelerated release testing methods, and stability of encapsulated drugs.

In vitro and in vivo evaluation of an ionic sensitive in situ gel containing nanotransfersomes for aripiprazole nasal delivery

In the current study, a composite in-situ gel formulation containing aripiprazole (APZ) loaded transfersomes (TFS) was developed for the intranasal brain targeting of APZ. APZ loaded TFS were prepared by applying the film hydration method and optimized using an irregular factorial design. The prepared formulations were optimized based on different parameters including particle size, polydispersity index (PdI), zeta potential, encapsulation efficiency (EE) and release efficiency (RE). The optimized APZ-TFS were distributed in an ion-triggered deacetylated gellan gum solution (APZ-TFS-Gel) and evaluated in terms of pH, gelling time, rheological properties and in-vitro release study. The therapeutic efficacy of the best APZ-TFS-Gel was then tested in the mice model of schizophrenia induced by ketamine by evaluating various behavioral parameters. The optimized formulation showed the particle size of 72.12 ± 0.72 nm, the PdI of 0.19 ± 0.07, the zeta potential of -55.56 ± 1.9 mV, the EE of 97.06 ± 0.10%, and the RE of 70.84 ± 1.54%. The in-vivo results showed that compared with the other treatment groups, there was a considerable increase in swimming and climbing time and a decrease in locomotors activity and immobility time in the group receiving APZ-TFS-Gel. Thus, APZ-TFS-Gel was found to have desirable characteristics for therapeutic improvement.

The Patient, Investigator, Nurse, Carer Questionnaire (PINC-Q): a cross-sectional, retrospective, non-interventional study exploring the impact of less frequent medication administration with paliperidone palmitate 3-monthly as maintenance treatment for schizophrenia

BACKGROUND

To understand the implications of switching from paliperidone palmitate 1-monthly (PP1M) to paliperidone palmitate 3-monthly (PP3M) treatment of schizophrenia from the perspective of four key stakeholders: patients, physicians, nurses and carers.

METHODS

This was a cross-sectional, retrospective, non-interventional study comprising a one-time questionnaire (PINC-Q) for adult patients (aged ≥18 years) with schizophrenia (International Classification of Diseases; ICD-10) and their physician, nurse and carer. Questionnaires were developed in association with patient and carer advocacy groups (GAMIAN and EUFAMI) and following an advisory board formed of psychiatrists and nurses. The degree of alignment between stakeholders was also examined.

RESULTS

Responses were received from a total of 224 evaluable patients. For most patients (88.4%), responses were received from at least two other stakeholders. Patients were moderately ill with mild-to-moderate lack of insight and had received PP1M for a mean (standard deviation [SD]) of 23.9 (21.28) months before switching to PP3M (duration mean [SD] 12.8 [3.72] months). The most frequently reported reasons to switch from PP1M to PP3M were 'to live life as normally as possible' and 'patient convenience'. Over 79% of responses within each stakeholder group stated that PP3M helped the patients, with increased patient activity and social involvement, improved frequency and quality of physician-patient and nurse-patient communication and decreased perceived stigma.

CONCLUSIONS

The results of this study add to the increasing body of evidence supporting the benefits of PP3M in a population of patients with schizophrenia representative of real-world clinical practice.

Long-acting injectable versus oral antipsychotics for the maintenance treatment of schizophrenia: a systematic review and comparative meta-analysis of randomised, cohort, and pre-post studies

BACKGROUND

Evidence of comparative benefits of long-acting injectable antipsychotics (LAIs) versus oral antipsychotics for schizophrenia has been inconsistent across study designs. The aim of this study was to evaluate the comparative benefits of LAIs versus oral antipsychotics in three study designs to inform clinical decision making.

METHODS

We did a comprehensive systematic review and meta-analysis comparing LAIs versus oral antipsychotics for schizophrenia covering three study designs: randomised controlled trials (RCTs), cohort studies, and pre-post studies. Our literature search was without language restrictions, in MEDLINE and PubMed, the Cochrane Library, Scopus, and Embase, for studies published from database inception up to a last search on March 13, 2020. We also searched for unpublished studies and ClinicalTrials.gov. We included studies lasting at least 6 months that targeted adults with schizophrenia and related disorders (>80% of participants). Studies on penfluridol (neither an LAI or daily oral antipsychotic), case reports, and case series with fewer than 20 patients were excluded. Two investigators independently extracted study-level data and resolved disagreement by consensus, or via a third investigator. Study authors were contacted to obtain additional information as needed. For our primary outcome we meta-analysed the risk ratio (RR) for hospitalisation or relapse with LAIs versus oral antipsychotics by a random-effects model, with hospitalisation used preferentially over relapse. As secondary analyses, we reversed the preferential order to relapse over hospitalisation, and assessed hospitalisation risk and relapse risk individually. Other secondary outcomes included all meta-analysable data, classed by relevance to effectiveness, efficacy, safety, quality of life, cognitive function, and other outcomes, and analysed by study design. Dichotomous outcomes were expressed as pooled RR and continuous outcomes as standardised mean difference (SMD). The protocol is registered with PROSPERO (CRD42019142094).

FINDINGS

We identified 14 687 records, of which 137 studies (397 319 patients) met the inclusion criteria (32 RCTs [23·4%; 8577 patients], 65 cohort studies [47·4%; 377 447 patients], and 40 pre-post studies [29·2%; 11 295 patients]) and were analysed. The quality of studies in terms of risk of bias varied across study designs and within each study design from low to high. LAIs were associated with a lower risk of hospitalisation or relapse than oral antipsychotics in each of the three study designs (RCTs: 29 studies, 7833 patients, RR 0·88 [95% CI 0·79-0·99], p=0·033; cohort studies: 44 studies, 106 136 patients, RR 0·92 [0·88-0·98], p=0·0044; pre-post studies: 28 studies, 17 876 patients, RR 0·44 [0·39-0·51], p<0·0001). This association was maintained across the study designs when we reversed the preferential order to risk of relapse over hospitalisation, and in individual analysis of hospitalisation risk. The association was maintained only in pre-post studies for relapse risk alone. In all other outcomes related to effectiveness, efficacy, safety, quality of life, cognitive function, and other outcomes, LAIs were more beneficial than oral antipsychotics in 60 (18·3%) of 328 comparisons, not different in 252 (76·8%) comparisons, and less beneficial in 16 (4·9%) comparisons when analysed by study design. Significant heterogeneity was observed across all three study designs. Publication biases were apparent in cohort and pre-post studies, but effect sizes were similar after trim-and-fill analyses.

INTERPRETATION

Although study designs have strengths and weaknesses, including potential low quality of observational studies, we consistently identified significant benefit with LAIs versus oral antipsychotics in preventing hospitalisation or relapse, in settings ranging from restricted research (RCTs) to real-word application (cohort and pre-post studies). Our findings suggest that increased clinical use of LAIs could improve outcomes in schizophrenia.

FUNDING

None.

TRANSLATIONS

For the Chinese, French, German, Italian, Japanese, Portugese and Spanish translations of the abstract see Supplementary Materials section.

Current and emerging long-acting antipsychotics for the treatment of schizophrenia

Introduction: In this review, the authors discuss the role of long-acting injectable antipsychotics (LAIs) for schizophrenia, focusing on the effectiveness and new perspectives introduced by such treatment strategy. Despite their promising pharmacokinetic features and their potential advantages in medication adherence, clinical outcomes, and medical costs, LAIs are not habitually presented as an option for patients, especially in the early phase of schizophrenia.Areas covered: This review explores the panorama of available LAIs for the treatment of schizophrenia, first-episode of psychosis, approved indications, medical costs, medication adherence, side effects, effectiveness and differences between first-generation (FGA)-LAIs and second-generation (SGA)-LAIs.Expert Opinion: LAIs differ in terms of specific indications, approved injection sites, needle size, injection volume, injection interval as well as potential drug-drug interactions, and commonly reported adverse reactions. The approved indications have expanded beyond schizophrenia to include bipolar and schizoaffective disorder. SGA-LAIs are often preferred to FGA-LAIs. FGA-LAIs although are less chosen in new patients due to the induction of cognitive and extrapyramidal side effects, even if, on the other hand, many SGA-LAIs are burden by hyperprolactinemia and weight gain. After a review of the available evidence, insight is provided into the potential and current therapeutic opportunities offered by LAI antipsychotic formulations.

Guidance on the clinical understanding and use of long-acting injectable antipsychotics in Schizophrenia: Hong Kong Consensus Statements

AIMS

There is increasing evidence showing the importance of long-acting injectable antipsychotics in the management of schizophrenia, especially in terms of improving patient medication compliance. A panel of experienced clinicians in Hong Kong mapped out a set of consensus statements with an aim to facilitate the understanding and use of long-acting injectable antipsychotics among local physicians.

METHODS

Eight discussion areas regarding long-acting injectable antipsychotics were selected by the chairman of the consensus group. A series of meetings were held for the panelists to discuss the published literature and their clinical experience, followed by the drafting of consensus statements. At the final meeting, each consensus statement was voted on anonymously by all members based on its practicability of recommendation in Hong Kong.

RESULTS

A total of 12 consensus statements on the rational use of long-acting injectable antipsychotics were established and accepted by the consensus group.

CONCLUSION

The consensus statements aim to provide practical guidance for Hong Kong physicians on the use of long-acting injectable antipsychotics in schizophrenia patients. These statements may also serve as a reference for doctors in other parts of the Asia-Pacific region.

Microemulsion-Based Media in Nose-to-Brain Drug Delivery

Nose-to-brain drug delivery has recently attracted enormous attention as an alternative to other delivery routes, including the most popular oral one. Due to the unique anatomical features of the nasal cavity, drugs administered intranasally can be delivered directly to the central nervous system. The most important advantage of this approach is the ability to avoid the blood-brain barrier surrounding the brain and blocking the entry of exogenous substances to the central nervous system. Moreover, selective brain targeting could possibly avoid peripheral side effects of pharmacotherapy. The challenges associated with nose-to-brain drug delivery are mostly due to the small volume of the nasal cavity and insufficient drug absorption from nasal mucosa. These issues could be minimized by using a properly designed drug carrier. Microemulsions as potential drug delivery systems offer good solubilizing properties and the ability to enhance drug permeation through biological membranes. The aim of this review is to summarize the current status of the research focused on microemulsion-based systems for nose-to-brain delivery with special attention to the most extensively investigated neurological and psychiatric conditions, such as neurodegenerative diseases, epilepsy, and schizophrenia.

Therapeutic Drug Monitoring of Long-Acting Injectable Antipsychotic Drugs

BACKGROUND

The use of therapeutic drug monitoring (TDM) to guide treatment with long-acting injectable (LAI) antipsychotics, which are increasingly prescribed, remains a matter of debate. The aim of this review was to provide a practical framework for the integration of TDM when switching from an oral formulation to the LAI counterpart, and in maintenance treatment.

METHODS

The authors critically reviewed 3 types of data: (1) positron emission tomography data evaluating dopamine (D2/D3) receptor occupancy related to antipsychotic concentrations in serum or plasma; D2/D3 receptors are embraced as target sites in the brain for antipsychotic efficacy and tolerability, (2) pharmacokinetic studies evaluating the switch from oral to LAI antipsychotics, and (3) pharmacokinetic data for LAI formulations. Based on these data, indications for TDM and therapeutic reference ranges were considered for LAI antipsychotics.

RESULTS

Antipsychotic concentrations in blood exhibited interindividual variability not only under oral but also under LAI formulations because these concentrations are affected by demographic characteristics such as age and sex, genetic peculiarities, and clinical variables, including comedications and comorbidities. Reported data combined with positron emission tomography evidence indicated a trend toward lower concentrations under LAI administration than under oral medications. However, the available evidence is insufficient to recommend LAI-specific therapeutic reference ranges.

CONCLUSIONS

Although TDM evidence for newer LAI formulations is limited, this review suggests the use of TDM when switching an antipsychotic from oral to its LAI formulation. The application of TDM practice is more accurate for dose selection than the use of dose equivalents as it accounts more precisely for individual characteristics.

Long-Acting Injectable Antipsychotics: A Systematic Review of Their Non-Systemic Adverse Effect Profile

INTRODUCTION

Long acting injectable (LAI) antipsychotics are commonly used in the treatment of schizophrenia to improve adherence and clinical outcomes. Concerns have been reported in relation to their non-systemic or injection site adverse effect profile. As such, this study aims to review and evaluate all evidence reporting injection site adverse effects with LAI antipsychotics.

METHODS

An electronic search was systematically conducted through four databases (PubMed, Embase, SCOPUS, Cochrane) in order to identify studies investigating injection-site reactions associated with LAI antipsychotics. Unpublished studies such as conference proceedings and clinical trial registries were also searched. The search was limited to literature published in English without year limits.

RESULTS

Of a total of 189 citations that were identified from the electronic database search, 12 were selected for inclusion in this review. Various injection site reactions were reported in these studies, including pain, bleeding, and swelling. Overall, the studies reported a low incidence of these injection site reactions. Only a minority of the included articles compared injection site reactions between different LAI antipsychotics.

CONCLUSION

Injection site pain was the most commonly reported injection site adverse effect across all articles reviewed. The low incidence of injection site adverse effects associated with LAI antipsychotics indicates that these formulations appear to be well tolerated by patients. More head-to-head trials comparing second generation LAI antipsychotics are needed.

Modulating target engagement of small molecules via drug delivery: approaches and applications in drug discovery and development

Drug-delivery technologies for modified drug release have been in existence for decades, but their utilization has been largely limited to post-launch efforts improving therapeutic outcomes. Recently, they have gained renewed importance because the pharmaceutical industry is steadily shifting to a more integrated discovery-development approach. In discovery, modulating target engagement via drug-delivery technologies can enable crucial pharmacological studies for building well-defined criteria for molecular design. In development, earlier implementation of delivery technologies can enhance the value of drug products through reduced dosing frequency and improved tolerability and/or safety profile, thereby leading to better adherence and therapeutic effectiveness.

Clinically established biodegradable long acting injectables: An industry perspective

Long acting injectable formulations have been developed to sustain the action of drugs in the body over desired periods of time. These delivery platforms have been utilized for both systemic and local drug delivery applications. This review gives an overview of long acting injectable systems that are currently in clinical use. These products are categorized in three different groups: biodegradable polymeric systems, including microparticles and implants; micro and nanocrystal suspensions and oil-based formulations. Furthermore, the applications of these drug delivery platforms for the management of various chronic diseases are summarized. Finally, this review addresses industrial challenges regarding the development of long acting injectable formulations.

Biomedical Implants for Regenerative Therapies

Regenerative therapies aim to develop novel treatments to restore tissue function. Several strategies have been investigated including the use of biomedical implants as three-dimensional artificial matrices to fill the defect side, to replace damaged tissues or for drug delivery. Bioactive implants are used to provide growth environments for tissue formation for a variety of applications including nerve, lung, skin and orthopaedic tissues. Implants can either be biodegradable or non-degradable, should be nontoxic and biocompatible, and should not trigger an immunological response. Implants can be designed to provide suitable surface area-to-volume ratios, ranges of porosities, pore interconnectivities and adequate mechanical strengths. Due to their broad range of properties, numerous biomaterials have been used for implant manufacture. To enhance an implant’s bioactivity, materials can be functionalised in several ways, including surface modification using proteins, incorporation of bioactive drugs, growth factors and/or cells. These strategies have been employed to create local bioactive microenvironments to direct cellular responses and to promote tissue regeneration and controlled drug release. This chapter provides an overview of current bioactive biomedical implants, their fabrication and applications, as well as implant materials used in drug delivery and tissue regeneration. Additionally, cell- and drug-based bioactivity, manufacturing considerations and future trends will be discussed.

Intra-Articular injection of acid-sensitive stearoxyl-ketal-dexamethasone microcrystals for long-acting arthritis therapy

Despite advances in treatment of chronic arthritis, there is still a strong need for the development of long-acting formulations that can enable local and sustained drug release at the inflamed tissues. In this work, we fabricated microcrystals of an acid-sensitive stearoxyl-ketal-dexamethasone prodrug for treatment of arthritis. Microcrystals of the prodrug with two sizes were successfully engineered and showed pH-dependent hydrolysis kinetics in vitro. In a collagen-induced arthritis rat model, we evaluated the influence of particle size and injection dose on anti-inflammatory effect after intra-articular injection. Such prodrug demonstrated long-acting anti-arthritis effects with good safety. Our results indicate ketal-based prodrugs are promising for the development of long-acting injectables and may stimulate the development of new treatments for chronic diseases.

Implant-forming polymeric 19F MRI-tracer with tunable dissolution

Magnetic resonance imaging (MRI) using ¹⁹F-based tracers has emerged as a promising multi-purpose noninvasive diagnostic tool and its application requires the use of various ¹⁹F-based tracers for the intended diagnostic purpose. In this study, we report a series of double-stimuli-responsive polymers for use as injectable implants, which were designed to form implants under physiological conditions, and to subsequently dissolve with different dissolution rates (t_1/2 ranges from 30 to more than 250 days). Our polymers contain a high concentration of fluorine atoms, providing remarkable signal detectability, and both a hydrophilic monomer and a pH-responsive monomer that alter the biodistribution properties of the implant. The implant location and dissolution were observed using ¹⁹F MRI, which allows the anatomic extent of the implant to be monitored. The dissolution kinetics and biocompatibility of these materials were thoroughly analyzed. No sign of toxicity in vitro or in vivo or pathology in vivo was observed, even in chronic administration. The clinical applicability of our polymers was further confirmed via imaging of a rat model by employing an instrument currently used in human medicine.

Signals of Adverse Drug Reactions of Paliperidone Compared to Other Atypical Antipsychotics Using the Korean Adverse Event Reporting System Database

BACKGROUND AND OBJECTIVES

Schizophrenia is a severe public health problem and one of the top ten causes of disability, affecting about 1.1% of the world's population. Paliperidone is a new atypical antipsychotic used to treat schizophrenia. Several case reports about unexpected adverse drug reactions of paliperidone have been consistently reported around the world. The purpose of this study was to detect signals of adverse events (AEs) after paliperidone treatment using the Korea Institute of Drug Safety and Risk Management-Korea Adverse Event Reporting System database (KIDS-KD).

METHODS

We applied data-mining techniques based on a disproportionality analysis to KIDS-KD consisting of spontaneously reported AE reports related to atypical antipsychotics between January 2009 and December 2018. We calculated three data-mining indices of paliperidone compared to all other atypical antipsychotics. We defined signals that satisfied all three criteria of the indices. We checked if the signals identified were included in the drug labels for South Korea, the USA, the UK, Japan, Germany, and France.

RESULTS

The total number of suspected AE reports related to all atypical antipsychotics in the KIDS-KD from January 2009 to December 2018 was 43,970. Among those, the number of AE reports related to paliperidone was 9453. Overall, 13 signals such as seborrhea, hallucination, obesity, gingivitis, and intervertebral disorder were classified into newly detected meaningful signals.

CONCLUSION

We detected new AE signals of paliperidone that were not listed on the drug labels of six countries, and many that were related to psychotic symptoms, metabolic problems, and endocrine disorders.

Injectable Lipid-Based Depot Formulations: Where Do We Stand?

The remarkable number of new molecular entities approved per year as parenteral drugs, such as biologics and complex active pharmaceutical ingredients, calls for innovative and tunable drug delivery systems. Besides making these classes of drugs available in the body, injectable depot formulations offer the unique advantage in the parenteral world of reducing the number of required injections, thus increasing effectiveness as well as patient compliance. To date, a plethora of excipients has been proposed to formulate depot systems, and among those, lipids stand out due to their unique biocompatibility properties and safety profile. Looking at the several long-acting drug delivery systems based on lipids designed so far, a legitimate question may arise: How far away are we from an ideal depot formulation? Here, we review sustained release lipid-based platforms developed in the last 5 years, namely oil-based solutions, liposomal systems, in situ forming systems, solid particles, and implants, and we critically discuss the requirements for an ideal depot formulation with respect to the used excipients, biocompatibility, and the challenges presented by the manufacturing process. Finally, we delve into lights and shadows originating from the current setups of in vitro release assays developed with the aim of assessing the translational potential of depot injectables.

Dopamine antagonist antipsychotics in diverted forensic populations

In community settings, negative symptoms and cognitive deficits are the primary barriers to independent living, stable relationships, and employment for individuals suffering from schizophrenia-spectrum disorders. In contrast, however, positive psychotic symptoms (e.g., command hallucinations and persecutory delusions) often drive behavior which serves as the gateway to arrest and criminalization. Historically, the keystone of treatment for positive psychotic symptoms has been antagonism of dopamine D2 receptors in the mesolimbic tract. In this article, we review and explore the principles underlying dopamine antagonism for the treatment of psychosis; optimization of dopamine antagonists in treating positive psychotic symptoms; the advantages of depot dopamine antagonist antipsychotics in forensic settings; the concepts of pharmacokinetic and pharmacodynamic treatment failures; and the role of medication plasma concentrations in optimizing and managing treatment.

Development of a Biodegradable Subcutaneous Implant for Prolonged Drug Delivery Using 3D Printing

Implantable drug delivery devices offer many advantages over other routes of drug delivery. Most significantly, the delivery of lower doses of drug, thus, potentially reducing side-effects and improving patient compliance. Three dimensional (3D) printing is a flexible technique, which has been subject to increasing interest in the past few years, especially in the area of medical devices. The present work focussed on the use of 3D printing as a tool to manufacture implantable drug delivery devices to deliver a range of model compounds (methylene blue, ibuprofen sodium and ibuprofen acid) in two in vitro models. Five implant designs were produced, and the release rate varied, depending on the implant design and the drug properties. Additionally, a rate controlling membrane was produced, which further prolonged the release from the produced implants, signalling the potential use of these devices for chronic conditions.

Efficacy and safety of paliperidone palmitate 3-month formulation in Latin American patients with schizophrenia: A subgroup analysis of data from two large phase 3 randomized, double-blind studies

Objective:

To analyze the efficacy and safety of paliperidone palmitate 3-monthly (PP3M) in Latin American patients with schizophrenia vs. rest-of-world (ROW).

Methods:

We analyzed data from two multinational, double-blind (DB), randomized, controlled phase 3 studies including patients with schizophrenia (DSM-IV-TR) previously stabilized on PP1M/PP3M (open-label [OL] phase). Patients were randomized to PP3M or PP1M (noninferiority study A) and PP3M or placebo (study B) in DB phase. The subgroup analysis included Latin American (Argentina, Brazil, Colombia, Mexico) patients. Primary efficacy endpoints were relapse-free rates (study A) and time-to-relapse (study B).

Results:

In study A, 63/71 (88.7%) and in study B 38/43 (88.4%) Latin American patients completed the DB phase. In study A, relapse-free percentage was similar in Latin America (PP3M: 97%, PP1M: 100%) and ROW (PP3M: 91%, PP1M: 89%). In study B, median time-to-relapse was not estimable in the Latin American subgroup for either placebo or PP3M groups, nor for the ROW PP3M group; the median time-to-relapse in the ROW placebo group was 395 days. Caregiver burden improved in patients switching from oral antipsychotics (OL baseline) to PP3M/PP1M in DB phase (Involvement Evaluation Questionnaire score mean ± SD change, -9.4±15.16; p < 0.001). Treatment emergent adverse events with PP3M during DB phase were similar in Latin America (study A: 24/34 [70.6%]; study B: 15/21 [71.4%]) and ROW (study A: 318/470 [67.7%]; study B: 84/139 [60.4%]) subgroups.

Conclusion:

PP3M was efficacious and showed no new safety concerns in patients with schizophrenia from Latin America, corroborating ROW findings.

Clinical trial registration:

NCT01515423, NCT01529515

Synthesis and Characterization of Long-Acting Darunavir Prodrugs

Antiretroviral therapy (ART) has improved the quality of life in patients infected with HIV-1. However, complete viral suppression within anatomical compartments remains unattainable. This is complicated by adverse side effects and poor adherence to lifelong therapy leading to the emergence of viral drug resistance. Thus, there is an immediate need for cellular and tissue-targeted long-acting (LA) ART formulations. Herein, we describe two LA prodrug formulations of darunavir (DRV), a potent antiretroviral protease inhibitor. Two classes of DRV prodrugs, M1DRV and M2DRV, were synthesized as lipophilic and hydrophobic prodrugs and stabilized into aqueous suspensions designated NM1DRV and NM2DRV. The formulations demonstrated enhanced intracellular prodrug levels with sustained drug retention and antiretroviral activities for 15 and 30 days compared to native DRV formulation in human monocyte-derived macrophages. Pharmacokinetics tests of NM1DRV and NM2DRV administered to mice demonstrated sustained drug levels in blood and tissues for 30 days. These data, taken together, support the idea that LA DRV with sustained antiretroviral responses through prodrug nanoformulations is achievable.

Clinical relevance of paliperidone palmitate 3-monthly in treating schizophrenia

Antipsychotics are the mainstay in schizophrenia management, and long-acting injectable (LAI) antipsychotics contribute to the successful maintenance of treatment by improving non-adherence and preventing relapses. Paliperidone palmitate 3-monthly (PP3M) formulation is the only available LAI antipsychotic that offers an extended 3-month window of stable plasma drug concentration, enabling only four injections per year. This paper summarizes clinically relevant endpoints from available evidence for PP3M to bridge translational research gaps and provide measurable outcomes that can be interpreted in clinical practice. Low number-needed-to-treat (NNT) for relapse prevention (NNT [95% CI] 6-month estimate: 4.8 [3.2; 10.0]; 12-month estimate: 3.4 [2.2; 7.0]), and high number-needed-to-harm (NNH [95% CI] akathisia, 27.1 [12.3; -667.1]; tremor, 80.0 [22.5; 67.3]; dyskinesia, -132.6 [44.5; -23.2]; parkinsonism, 160.0 [28.9; -49.8]) quantify the relative benefits and low propensity for adverse events with PP3M. Symptom remission and reductions in positive and negative symptoms indicate treatment stability. Additionally, meaningful functional remission, reduced dosing frequency, and freedom from daily negotiations favorably impact patient preference and attenuate burdensome aspects of caregiving, representing important healthcare determinants that enhance prospects of treatment continuity in schizophrenia. This information can potentially improve clinicians' judgment of treatment choices, clinical response, and patient selection in routine care. Taken together, PP3M is a valuable antipsychotic treatment option, meriting consideration for a broader role in the long-term management of schizophrenia; its utility should not be limited to patients with poor adherence or when oral antipsychotics have failed.

Activity of a Long-Acting Injectable Bedaquiline Formulation in a Paucibacillary Mouse Model of Latent Tuberculosis Infection

The potent antituberculosis activity and long half-life of bedaquiline make it an attractive candidate for use in long-acting/extended-release formulations for the treatment of latent tuberculosis infection (LTBI). Our objective was to evaluate a long-acting injectable (LAI) bedaquiline formulation in a validated paucibacillary mouse model of LTBI.

The potent antituberculosis activity and long half-life of bedaquiline make it an attractive candidate for use in long-acting/extended-release formulations for the treatment of latent tuberculosis infection (LTBI). Our objective was to evaluate a long-acting injectable (LAI) bedaquiline formulation in a validated paucibacillary mouse model of LTBI. Following immunization with Mycobacterium bovis rBCG30, BALB/c mice were challenged by aerosol infection with M. tuberculosis H37Rv. Treatment began 13 weeks after challenge infection with one of the following regimens: an untreated negative-control regimen; positive-control regimens of daily rifampin (10 mg/kg of body weight), once-weekly rifapentine (15 mg/kg) and isoniazid (50 mg/kg), or daily bedaquiline (25 mg/kg); test regimens of one, two, or three monthly doses of LAI bedaquiline at 160 mg/dose (B_LAI-160); and test regimens of daily bedaquiline at 2.67 mg/kg (B_2.67), 5.33 mg/kg (B_5.33), or 8 mg/kg (B₈) to deliver the same total amount of bedaquiline as one, two, or three doses of B_LAI-160, respectively. All drugs were administered orally, except for B_LAI-160 (intramuscular injection). The primary outcome was the decline in M. tuberculosis lung CFU counts during 12 weeks of treatment. The negative- and positive-control regimens performed as expected. One, two, and three doses of B_LAI-160 resulted in decreases of 2.9, 3.2, and 3.5 log₁₀ CFU/lung, respectively, by week 12. Daily oral dosing with B_2.67, B_5.33, and B₈ decreased lung CFU counts by 1.6, 2.8, and 4.1 log₁₀, respectively. One dose of B_LAI-160 exhibited activity for at least 12 weeks. The sustained activity of B_LAI-160 indicates that it shows promise as a short-course LTBI treatment requiring few patient encounters to ensure treatment completion.

Development and evaluation of intramuscularly administered nano/microcrystal suspension

INTRODUCTION

Formulation of nanocrystals is one of the most important drug delivery systems for poorly soluble drug molecules. Nanocrystals are produced by techniques like precipitation, media milling, high-pressure homogenization, and so on. In order to achieve sustained release and higher absorption of nanosuspensions, intramuscularly administered nanosuspensions have been developed. As well, intramuscularly administered nanosuspensions have been implemented in order to improve the bioavailability of drug nanocrystals which have both a low oral bioavailability and cannot be administered by intravenous injection routes.

AREAS COVERED

This review summarizes studies that have focused on the production, classification, in vitro release and in vivo pharmacokinetics of intramuscularly administered nanosuspensions. In order to avoid common drawbacks of intramuscularly administered nanosuspensions, such as tissue residues and some local tissue damage, nanosuspensions with a reduced administration volume of high drug loading and extended therapeutic effects are developed.

EXPERT OPINION

Intramuscularly administered nano/micro crystal suspensions have been developed for the treatment of various diseases such as schizophrenia, hormone disordered diseases, HIV and more. Additionally, intramuscularly administered nanosuspensions are also a good route for the development of traditional chinese medicines which have lower oral bioavailability and are not suitable for intravenous injection.

Tuning HIV drug release from a nanogel-basedin situforming implant by changing nanogel size

This paper reports anin situforming implant based on responsive nanogels that gives tuneable long-acting drug release.

Risperidone Controlled Release Microspheres Based on Poly(Lactic Acid)-Poly(Propylene Adipate) Novel Polymer Blends Appropriate for Long Acting Injectable Formulations

The present study evaluates the preparation of risperidone controlled release microspheres as appropriate long-acting injectable formulations based on a series of novel biodegradable and biocompatible poly(lactic acid)⁻poly(propylene adipate) (PLA/PPAd) polymer blends. Initially, PPAd was synthesized using a two-stage melt polycondensation method (esterification and polycondensation) and characterized by 1H-NMR, differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD) analyses. DSC and XRD results for PLA/PPAd blends (prepared by the solvent evaporation method) showed that these are immiscible, while enzymatic hydrolysis studies performed at 37 °C showed increased mass loss for PPAd compared to PLA. Risperidone-polyester microparticles prepared by the oil⁻water emulsification/solvent evaporation method showed smooth spherical surface with particle sizes from 1 to 15 μm. DSC, XRD, and Fourier-transformed infrared (FTIR) analyses showed that the active pharmaceutical ingredient (API) was dispersed in the amorphous phase within the polymer matrices, whereas in vitro drug release studies showed risperidone controlled release rates in all PLA/PPAd blend formulations. Finally, statistical moment analysis showed that polyester hydrolysis had a major impact on API release kinetics, while in PLA/PPAd blends with high PLA content, drug release was mainly controlled by diffusion.