---
title: "Long-Acting Injectable Development"
id: "2068"
type: "page"
slug: "long-acting-injectable-development"
published_at: "2026-11-06T11:47:33+00:00"
modified_at: "2026-11-06T12:27:30+00:00"
url: "https://innocorepharma.com/long-acting-injectable-development/"
markdown_url: "https://innocorepharma.com/long-acting-injectable-development.md"
---

# Long-Acting Injectable Development

Developing a long-acting injectable requires more than extending the release of an active pharmaceutical ingredient. Achieving sustained drug release requires balancing API stability, release kinetics, polymer selection, manufacturability and scalability within a development strategy that is appropriate for the molecule and its target product profile. Small formulation changes can significantly influence product performance, making an integrated development approach essential.

Innocore supports pharmaceutical and biotechnology companies in the development of long-acting injectable dosage forms through its proprietary SynBiosys® biodegradable polymer platform. Combining formulation science, polymer expertise, analytical development and manufacturing know-how, Innocore helps development teams assess technical feasibility and advance promising formulations towards further development and GMP production.

## What is long-acting injectable development?

Long-acting injectable development involves designing an injectable dosage form that releases an active pharmaceutical ingredient over an extended period. Depending on the molecule, formulation and delivery platform, the intended release period may range from a week to several months.

Different approaches can be considered, including microspheres, implants, in situ forming depots and injectable gel systems. The suitability of a technology depends on factors such as the physicochemical properties of the API, its stability during processing and release, the required drug load and the target release profile.

These factors are interdependent. A formulation that produces a promising release profile at laboratory scale must also be sufficiently stable, reproducible and suitable for further scale-up. Long-acting injectable development therefore requires coordinated decisions across formulation, analytics, process design and manufacturing.

## Starting with the molecule and target product profile

Every development program begins with a different molecule, set of constraints and intended target product profile. Before selecting a formulation approach, the development team must understand the relevant characteristics of the API and determine which technical risks need to be addressed first.

Important considerations may include molecular size, solubility, sensitivity to temperature or solvents, aggregation risk, dose requirements and the desired duration of release. These properties influence both the selection of the delivery platform and the design of the initial experiments.

Through **pharmaceutical formulation development**, formulation concepts can be screened across various polymer grades and iteratively refined around the specific characteristics of the molecule.

This work helps establish whether the API can be incorporated into a suitable long-acting dosage form while retaining the quality attributes required for continued development.

## Selecting an appropriate drug delivery approach

No single long-acting injectable technology is suitable for every API. Microspheres, in situ forming depots and gels each rely on different formulation principles and manufacturing processes, resulting in distinct release profiles.

Selecting an appropriate platform requires a structured comparison of technical options. The delivery system must accommodate the molecule, support the intended drug load and produce a release profile that can be controlled and reproduced. Practical factors such as administration, sterilisation strategy, process complexity and future scale-up also need to be considered.

Innocore’s **drug delivery development** capabilities support the evaluation and development of controlled-release approaches for complex active pharmaceutical ingredients. The objective is not simply to select a technology, but to identify a formulation strategy that can remain viable throughout the wider development program.

## Managing the key formulation challenges

Long-acting injectable formulations introduce scientific challenges that may not occur in conventional immediate-release products due to the need to be stable over a longer period, while at the same time, the formulation must deliver a controlled and sufficiently reproducible release profile.

Development teams may need to investigate:

- API stability during formulation, processing, storage and release;
- compatibility between the API, polymer and other formulation components;
- initial burst release and subsequent release kinetics;
- drug loading and encapsulation efficiency;
- particle size, viscosity or implant dimensions;
- swelling and degradation behaviour of the delivery matrix;
- reproducibility across formulation batches;
- the feasibility of sterile production and scale-up.

These questions cannot be addressed in isolation. Changing the polymer composition or manufacturing conditions may improve one characteristic while negatively affecting stability, processing or release. A risk-based experimental strategy is therefore needed to identify the formulation and process parameters that matter most.

## Discuss your long-acting injectable development program

[Contact Innocore](https://innocorepharma.com/contact-us/)

## Building a reproducible and scalable process

A successful laboratory formulation is only one step in the development of a long-acting injectable. The way the product is manufactured can directly influence critical attributes such as particle size, drug distribution, residual solvent levels, morphology and release behaviour.

During **process development**, manufacturing parameters are evaluated and refined to improve control, robustness and reproducibility. This may involve identifying critical process parameters, defining acceptable operating ranges and determining how changes in equipment or batch size affect the formulation.

Considering scalability early can reduce the risk of developing a formulation that performs well at small scale but requires substantial redesign before clinical manufacturing. The formulation and its manufacturing process should therefore evolve together rather than as separate workstreams.

## Using analytics to guide development decisions

Analytical methods provide the evidence needed to compare formulations, understand degradation pathways and monitor critical quality attributes. For long-acting injectables, development may require more than conventional identity, purity and assay testing.

Depending on the dosage form, relevant analytical work may include release testing, molecular integrity, polymer characterisation, particle size analysis, residual solvent testing, drug content, encapsulation efficiency and physical characterisation of the finished formulation.

Innocore’s **analytical development** activities are intended to support formulation and process decisions throughout the program. Methods and datasets should be sufficiently informative to distinguish between formulation options, investigate unexpected results and support the transition towards later development stages.

## Preparing the product and process for transfer

As a program moves beyond early development, scientific and process knowledge must be documented in a form that can be transferred to another team, facility or manufacturing environment. This includes not only the selected formulation, but also the rationale behind key decisions, the relevant process parameters and the analytical controls used to evaluate product quality.

Effective **technology transfer** helps preserve development knowledge and reduces the risk of avoidable variation when a process is introduced at a different scale or site. Transfer planning is particularly important for complex long-acting dosage forms, where small changes in materials, equipment or processing conditions can affect product characteristics.

## Manufacturing support across development stages

Manufacturing requirements depend on the stage and purpose of the program. Material intended for non-clinical work, analytical studies or clinical evaluation may require different quality systems, controls and documentation.

Innocore can connect development activities with appropriate manufacturing preparation through its broader **CDMO services**.

Where relevant to the program, this may include **GLP manufacturing** support for material intended for in-vivo and other non-clinical studies, as well as **GMP manufacturing** for material produced under applicable Good Manufacturing Practice (GMP) requirements.

The specific route depends on the product, development phase and intended use of the manufactured material. Quality and regulatory requirements should therefore be confirmed for each individual program rather than assumed from a standard development pathway.

## An integrated approach to long-acting injectable development

Long-acting injectable development is most effective when formulation, analytics, process design and manufacturing are considered as connected disciplines. Decisions made during early feasibility work can have consequences for scale-up, analytical control, technology transfer and future production.

Innocore brings these disciplines together within a development approach centred on the characteristics of the API and the objectives of the program. This allows technical risks to be identified early and helps create a clearer route from initial formulation concepts towards scalable long-acting injectable dosage forms.

## Long-acting injectable technologies

The appropriate dosage form depends on the molecule and target product profile. Innocore develops long-acting injectable formulations using its proprietary SynBiosys® and Ingell® polymer platforms – which are used for several dosage forms:

- **Microspheres**
- **In situ forming depots**
- **Gels**
- **Implants**

## Frequently asked questions about long-acting injectable development

What is a long-acting injectable? + A long-acting injectable is an injectable dosage form designed to release an active pharmaceutical ingredient over an extended period. The intended release duration and release profile depend on the API, formulation, dosage form and, for polymer-based delivery systems, the design and properties of the polymer.

  Which APIs can be considered for long-acting injectable development? + Long-acting injectable approaches can be investigated for different types of active pharmaceutical ingredients, including peptides, biologics and small molecules. Technical feasibility must be evaluated for each API because stability, drug loading, processing requirements and release behaviour vary between molecules.

  Which technologies can be used for long-acting injectables? + Potential technologies include microspheres, implants, in situ forming depots and injectable gels. Platform selection depends on the API, target release profile, dose, route of administration and manufacturing requirements.

  Why should process development begin early? + The manufacturing process can affect important formulation characteristics and release behaviour. Evaluating process parameters and scalability during development can help identify risks before a formulation progresses to larger-scale or regulated manufacturing.

  How long does long-acting injectable development take? + There is no standard development timeline. As an indication, a feasibility project typically takes around six months, although timelines vary depending on the properties of the API, the complexity of the dosage form, analytical requirements, formulation performance and the intended stage of manufacture.

## Discuss your long-acting injectable development program

Whether you are evaluating the feasibility of a long-acting injectable, comparing delivery technologies or preparing a formulation for clinical development, early technical decisions have a lasting impact on product performance and manufacturability. Innocore combines formulation science, proprietary polymer technology, analytical development and manufacturing expertise to help pharmaceutical and biotechnology companies develop scalable long-acting injectable products.

[Contact Innocore](https://innocorepharma.com/contact-us/)