Importance of Preformulation Studies in Designing Formulations for Sustained Release Dosage Forms

Recently sustained release dosage forms has become standards in the modern pharmaceutical design and intensive research has been undertaken in achieving much better drug product effectiveness. The sustained release product will optimize therapeutic effect and safety of a drug at the same time improving patient convenience and compliance. Prior to the development of these major dosage forms, it is essential that pertain fundamental physical and chemical properties of the drug molecule and other divided properties of the drug powder are determined Preformulation is to provide and understand information regarding:1)the degradation process 2)any adverse conditions relevant to the drug 3)bioavailability 4)pharmacokinetics and formulation of similar compounds 6)toxicity. Preformulation influences a)selection of the drug candidate itself b)selection of formulation components c)API and drug product manufacturing processes d)determination of the most appropriate container closure system e)development of analytical methods f)assignment of API retest periods g)the synthetic route of API h)toxicological strategy. It also gives directions for the development of formulation in choice of drug form, excipients, composition, physical structure, helps in adjustment of pharmacokinetics and biopharmaceutical properties, support for PAT (process analytical technology). The overall objective of preformulation studies is to generate information useful in developing stable and bioavailable and sustained release dosage forms which can be mass produced.