How do Long-Acting Injectable Antipsychotics Work?

May 29, 2024

Long-acting injectable (LAI) antipsychotics are a class of medication first developed in the 1960s. The goal was to administer a dose of medication that would release continuously and sustainably over a longer period of time. Balancing medication release in this manner creates sustainable blood levels, and can lower the likelihood of potential relapses compared with oral-administered antipsychotics. Moreover, long-acting injectable antipsychotics can decrease the chance of patients requiring the help of an emergency clinic or being hospitalised.

Below, we will offer more detail about microsphere-based long-acting injectable antipsychotics and their in general.

Antipsychotics Injectable Drugs Syringe

Understanding Microsphere-Based Antipsychotics

Microsphere-based antipsychotics utilise biodegradable polymers, such as poly(lactic-co-glycolic acid) (PLGA), to encapsulate the active pharmaceutical ingredient. Upon injection, these microspheres gradually degrade, allowing for a controlled release of the antipsychotic drug over extended periods. This innovative approach addresses one of the most challenging aspects of schizophrenia treatment: ensuring consistent medication adherence over time.

Isoperidone: A Novel Approach
Recent research introduces Isoperidone, a prodrug of paliperidone, developed for PLGA-based microspheres to achieve a near-zero-order release behaviour. In a seminal study by Zhao et al., Isoperidone demonstrated a sustained suppressive effect on schizophrenic behaviour in a mouse model over two weeks. This finding underscores the potential of Isoperidone microspheres as a valuable alternative for clinical treatment. It promises a more predictable and steady therapeutic effect compared to traditional delivery methods.

Risperidone Microsphere Injection
Risperidone long-acting injection (RLAI) stands as the first long-acting atypical antipsychotic. It combines the long-acting benefits of conventional antipsychotics with the improved safety and efficacy profile of oral atypical antipsychotics. RLAI exhibits stable plasma levels, translating to enhanced health-related quality of life and social performance. The consistent drug levels achievable with RLAI mitigate the fluctuations often seen with oral dosing. This can lead to periods of suboptimal therapeutic coverage.

Comparative Efficacy and Systemic Reviews

A comparative study among veterans sheds light on the real-world effectiveness of risperidone microspheres. The study findings reveal that veterans receiving risperidone microspheres had fewer psychiatric hospitalisations post-treatment. There was also a lower likelihood of rehospitalisation compared to those treated with paliperidone palmitate. These outcomes highlight the critical role of risperidone microspheres in maintaining psychiatric stability, offering a compelling argument for their preference in clinical settings.²
The superiority of long-acting injectable antipsychotics over oral formulations is further evidenced by a systematic review and meta-analysis from Kishimoto et al. This comprehensive study underscores the significant advantage of long-acting injectable formulations in preventing hospitalisations for schizophrenia. Therefore it affirms their pivotal role in the management of this challenging disorder.

Clinical Implications and Future Directions

The development of microsphere-based long-acting injectable antipsychotics marks a significant advancement in the therapeutic landscape of schizophrenia and related psychotic disorders. By offering sustained drug release and stable plasma levels, these formulations enhance patient compliance and promise improved therapeutic outcomes. As research continues to unveil novel microsphere-based antipsychotics, the focus must also extend to optimising these formulations for individual patient needs. That way patients can receive personalised and effective treatment strategies.

The evolution of microsphere technology and its application in antipsychotic therapy underscore the importance of innovative drug delivery systems in psychiatric care. Future investigations should aim to expand the repertoire of drugs available in microsphere-based long-acting injectable formulations. This includes exploring their potential in treating a broader spectrum of psychiatric conditions.

Making a Difference Through the Capabilities of Long-Acting Injectable Antipsychotics

With the creation of new technology, like microsphere-based, long-acting injectable antipsychotics, comes the opportunity to help patients manage mental illness. It is important that we utilise long-acting injectable antipsychotics carefully, employing them to help those in need, such as patients with schizophrenia, to take control of their treatments and ensure they receive the right levels of medication.

Here at Powder Systems, we want to improve the process behind how medication is delivered to the body. This is through the creation of microspheres. Already, you have seen how long-acting injectable antipsychotics can utilise microspheres to create an efficient schedule of medication delivery. By using our MSR™ MicroSphere Refiner, you can improve the quality of the microspheres encasing your medications. Work with us, Powder Systems, now to ensure that your microspheres can deliver the best results.

Alternatively, if you are interested in learning more about long-acting injectables, read our blog post on long-acting injectable drug processing, or contact a member of the Powder Systems Limited (PSL) team today.