Skip Navigation LinksDivisions > Pharmaceutical > Formulation Guides > Sustained Release

Sustained release

Sustained release (or extended-release) formulations create a steady drug release profile making the drug substance available over an extended period of time following ingestion.

Advantages of sustained release formulations include :

  • Uniform release of drug substance over time
  • Reduction in frequency of intakes
  • Reduced adverse side effects
  • Better patient compliance

A sustained release dosage form can be created using lipid excipients to form either a water insoluble matrix or a hydrophobic film around an active drug.

Formulation techniques include:

  • Compression
  • Capsule filling
  • Other Methods
    • Melt granulation/melt extrusion
    • Spray-cooling

Compression

When developing a sustained release tablet the main considerations are:

  • Determining the optimal ratio of drug to excipient
  • Establishing the tabletting parameters (e.g. compression force)
  • The stability of the release profile

The development process is as follows:

  1. Screen various levels of lipid matrix (e.g. Compritol 888 ATO) in order to achieve the desired drug release profile
  2. Define the exact T0 by comparing an uncured tablet versus a cured tablet *
    • If identical :
      • Continue the formulation development
    • If different
      • Evaluate the curing time required to achieve stabilisation
      • Optimise the release profile with the use of dual matrix , or with other excipients

*Crystalline changes in the lipid matrix could affect release profile. The phenomenon is often related to drug/excipient interaction. The release profile can be optimised and stabilised by curing the tablets or adding stabilisation agents.

For additional information on tablet curing and suitable stabilisation agents please contact us  

Capsule filling

A sustained release lipid matrix can be developed using a simple capsule filling technique.

Medium to high melting point excipients (39 -56 °C) are capable of forming a sustained release lipid matrix without help from an adjuvant.

Method :

  1. Heat semi-solid excipients (at least 20°C above the MP)
  2. Incorporate the active drug while stirring (solution/dispersion)
  3. Fill the molten mixture in hard gelatin capsule
    • (filling temperature = +2°C above the inflexion T°C from thermorheogram)
  4. Cool to ambient temperature (at least 12h before any evaluation)

Suitable excipients:

  • Precirol® ATO 5, Gelucire® 43/01, Gelucire® 39/01, Gelucire® 50/02, Gelucire® 50/13

Other techniques

Melt granulation/ Extrusion :

  • Suitable excipients: Compritol 888 ATO, Precirol ATO 5, Gelucire 33/01, Gelucire 39/01, Gelucire 43/01
  • Dose forms: Granules/Pellets

Spray-cooling :

  • Suitable excipients : Compritol 888 ATO, Precirol ATO5
  • Dose forms: Powders

Technical support

Please contact us or complete an enquiry form to request:

  • Practical guidelines for the development of SR dosage forms
  • Further product handling, regulatory and toxicology information
  • Details of the technical services offered by Gattefossé’s Application Laboratory

For Gattefossé’s full range of lipid excipients for sustained release formulations see sustained release