In the earlier chapter, Polymers definition, and Polymer classification, we discussed that Polymers are classified according to their origin, biostability, reaction mode of polymerization, and water interaction. We will now review the Properties and advantages of Pharmaceutical Polymers.
The polymer is incorporated with the pharmaceutically active ingredient to modify the release kinetics, carrier accumulation, or for active or passive targeting of the latter in the human body. Due to these capabilities, polymers can also be considered the backbone of the pharmaceutical drug delivery systems.
Properties of Pharmaceutical Polymers :
- Pharmaceutical polymers must be inert and compatible with the biological environment.
- It must be non – toxic and non -antigenic.
- Polymers should be biodegradable or completely eliminated from the site of application after the therapeutic action is over. Read about Polymers Applications in controlled release of Medicines
- It must be easy to fabricate and inexpensive to manufacture.
- Polymers must be compatible with a large number of drugs and have good mechanical strength.
- It must not adversely or negatively affect the release characteristics of the therapeutically active ingredient.
- It should be able to adhere or conjugate with the drug adequately and possess release sites for drug–polymer linkages. These linkages must be reversible to facilitate the drug release at the site of action.
- The polymer used must have a definite molecular weight and suitable glass transition temperature depending on the dosage form to be formulated. Eg. The glass transition temperature of polymers used in chewable solid dosage forms must be close to 37 degrees Celsius to ensure that the dosage form is soft and flexible at mouth temperature.
Pharmaceutical Polymers Advantages
Advantages of pharmaceutical polymers in controlled drug delivery systems :
Controlled drug delivery systems have advantages over the traditional dosage forms, thus they are gaining momentum in the last few decades. these are:
The better absorption rate, biocompatibility, cell and tissue-specific targeting of drugs, protection of medicine against degradation by proteolytic enzymes, and a longer duration of action of these dosage forms; are significant advantages of this drug system delivery. However, these attributes are conferred to the controlled drug delivery system by adding suitable polymers.
Pharmaceutical polymers are integral in the formulation of controlled drug delivery systems as they facilitate the constant release of drugs in a synchronized manner over a prolonged period. They modify the pharmacokinetics and pharmacodynamic properties of the biopharmaceuticals to improve the latter’s pharmacological activity. This modification is done via either one or more of the following ways:
- Increasing the plasma half-life of the biopharmaceutical
- Decreasing the immunogenicity of the active ingredient
- Enhancing the stability of the biopharmaceutical
- Improving the solubility of low molecular weight drugs
- Promoting the gradual release of the drug at the site of action.