The concept of preformulation is used in the field of pharmacy to refer to the development of research aimed at determining the compatibility of the substances that make up a pharmaceutical form . This work is key to obtaining a final product that is capable of meeting its specific objectives.
It should be remembered that the pharmaceutical form or galenic form is established from a precise combination of substances to allow the administration of a medication to be easier. This shape makes the active ingredients and excipients of the drug adapt to a certain arrangement.
Preformulation seeks to provide useful information for the proper development of the formulation. That is why it includes multiple studies on the composition and presentation of drugs .
Among the issues analyzed in the preformulation stage are the physical and chemical properties of the medications . Solubility , stability and reactivity, for example, are carefully observed.
Another aspect that is considered in preformulation is the ability of the substances to reach the point of action and thus achieve the triggering of the intended biological response .
It is common for preformulation to be associated with quality control . This work, which includes the choice of the most appropriate active ingredients, excipients, manufacturing process and packaging, enables the final product to meet the stated needs. The preformulation also contemplates the definition of the toxicological strategy, establishing what the limits of the components are.
Pharmaceutical development is essential today, since for decades we have depended on drugs to maintain and improve our state of health . In particular, this field seeks the development of products (medicines) that meet a well-defined set of requirements: elegance from a pharmaceutical perspective; the uniformity of its content; stability throughout their life (previously estimated); that they have adequate bioavailability; that can be produced in the corresponding industry.
Reviewing the objectives of the preformulation, we can say that the information it aims to provide must be useful for the following points:
* the proper development of the formulation, and this includes the form in which the drug in question is presented (polymorph, salt, etc.), its composition, its physical structure and its excipients;
* the process in which the definitive form of the medication and the final product must be obtained. This point includes other phases, such as filtration and the technological process;
* find a drug whose biopharmaceutical behaviors respond to a well-defined set of expectations;
* development of so-called analytical methods to quantify medications, control their purity , including their impurities and degradation products. These methods must be simple, sensitive, specific, and reproducible to be considered valid in the process.
With all this information we can move on to the creation of a preformulation program, which addresses certain activities that test the viability of the dosage and give rise to a series of studies mentioned above to define the properties:
* chemical : here the first branch is presented, which can lead to a solid , a liquid or a gas. In the case of a solid, its shape, its base and its type of salt, among other aspects, must be studied. Organoleptic properties, reactivity, purity and stability (pH, humidity, etc.) also come into play;
* physical : the description of its structure in a diagram, the characteristics of fluidity, static electricity and its particles, its crystalline structure and certain variables such as its partition coefficient, the speed of its dissolution and its solubility;
* biological : the ability of the drug to gain access to the point of action and give rise to the expected biological response.