REVIEW ON APPLICATIONS OF POLYMERS IN PHARMACEUTICAL FORMULATIONS

About Authors:
Darveshwar Jagdeep D*, Mule Madhav S1, Birajdar Shivprasad M2
*NRI Institute of Pharmaceutical Science, Bhopal, India
1School of Pharmacy, Swami Ramanand Teerth Marathwada University
Vishnupuri, Nanded-431606, Maharashtra, India,
2Department of Quality Assurance, Maharashtra College of Pharmacy,
Nilanga-413521, Maharashtra, India
*jagdeepdd@hotmail.com, birajdar100@gmail.com

Abstract:
Polymers have played indispensable roles in the preparation of pharmaceutical products. Their applications range widely from material packaging to fabrication of the most sophisticated drug delivery devices. This review includes various polymers used in pharmaceutics based on their applications. The review focuses on the use of pharmaceutical polymer for controlled drug delivery applications. Examples of pharmaceutical polymers and the principles of controlled drug delivery are outlined and applications of polymers for controlled drug delivery are described. The field of controlled drug delivery is vast therefore this review aims to provide an overview of the applications of pharmaceutical polymers. General pharmaceutical applications of polymers in Dental Medicine, Ophthalmic Drug Delivery, Gene Delivery, Preparation of micro spheres etc. are also discussed briefly.

Reference Id: PHARMATUTOR-ART-1509

INTRODUCTION
Life on Earth is linked to the presence of water, and water is our main constituent. However, all kinds of living species are not simply ‘bags of water’ but are highly organized. This specialized organization depends on other compounds, macromolecules, i.e. polymers that are able to retain and structure water, as natural hydro gels. Many polymers have a natural origin (mineral, vegetal or animal). Some of these have been used for centuries. In the vegetal kingdom, cellulose is the most abundant macromolecule. Cellulose is a polysaccharide composed of repeating units of cellobiose, i.e. it is a dimer of glucose. In the animal kingdom, chitin, a polymer of N-acetyl glucosamine, is widely distributed as the main constituent of the shell of arthropods. Proteins and nucleic acids are well known as supports of life, and these natural polymers retain and structure water. Use, including in the biomedical and pharmaceutical fields. An even wider diversity of properties and uses has been obtained with the development of synthetic polymers, which can be prepared by different methods and processes of polymerization of one or more monomers. In the domain of health, a very interesting property of purely synthetic polymers is their absence of immunogenicity, unlike many polymers of natural origin.

Definition
“Polymers are long chain organic molecules assembled from many smaller molecules called as monomers.”

In pharmaceutical preparations also they have several applications in mfg of bottles, syringes, vials, catheters, and also in drug formulations

Classification

A. Based on origin:
a)      Natural Polymers: e.g. Proteins – Collagen, Keratin, Albumin Carbohydrates – starch, cellulose, glycogen.
b)      Synthetic Polymers: e.g. polyesters, polyanhydrides, polyamides.

B. Based on Bio-stability:
a)   Bio-degradable Polymers:
E.g. polyesters, proteins, carbohydrates, etc

b)   Non – biodegradable Polymers:
E.g. ethyl cellulose, HPMC, acrylic polymer

Characteristics of Ideal Polymer

  1. Should be inert and compatible with the environment.
  2. Should be non-toxic.
  3. Should be easily administered.
  4. Should be easy and inexpensive to fabricate.
  5. Should have good mechanical strength

APPLICATIONS IN CONVENTIONAL DOSAGE FORMS
In Solid Dosage Forms,
1.   Tablets
2.   Capsules
3.   Film Coatings of Solid Dosage Forms
4.   Disperse Systems
5.   Gels
6.      Transdermal Drug Delivery Systems (Patches)

Tablets
In tablet the polymer are used as a Binder and Disintegrants. Binders which bind the powder particle in a damp mass various polymer are used are Ethyl cellulose, HPMC, Starch, Gelatin, polyvenylpyrrolidine. Alginic acid, Glucose, Sucrose. Disintegrates like Starch, cellulose, Alginates, polyvenylpyrrolidine, sodium CMC which decrease the time of dissolution and gives fast action of drug.

Capsules
The various polymer are used in the capsule as the plasticizer on which the flexibility and strength of the Gelatin are depend on it .The release rate of the Capsule are controlled by using the various type of polymer.

Naturalcoating agents
Natural polymer like Shellac and zein, although still used from time to time, are hardly able to meet present-day requirements. Organic solvents should be reserved for special applications only and chlorinated hydrocarbons such as methylene chloride and chloroform are avoided altogether, since they impose a heavy load on the environment. Low-molecular-weight types of methylcellulose and hydroxypropyl methylcellulose can also be processed as aqueous solutions. Ethyl cellulose and cellulose acetate phthalate are available as aqueous dispersions, so-called pseudolatexes. An overview of the most widely used cellulosic’s is presented, the structure and properties of acrylic polymers.

The solubility properties of EUDRAGIT® acrylic polymers are adjusted to the conditions of the digestive tract. They satisfy particularly stringent requirements in terms of purity. Further quality characteristics are the high stability to environmental influences during storage and absolute skin friendliness, i.e. indifference to bodily tissue and fluids. The amount of acrylic polymer consumed with the active ingredient is very small, only a few milligrams in the case of coated tablets and approximately 150 mg per day with specific sustained-release preparations. The average polymer quantity taken up by an adult is thus about 2 mg per kg of body weight.

Disperse Systems
The biphasic system are like emulsion, suspension use various polymer for disperse one phase into another phase i.e. water phase disperse in oil phase or vice versa the polymer like poly vinyl pyrolidine, ethyl cellulose etc. Dispersed Systems consist of particulate matter known as the dispersed phase, distributed throughout the dispersion medium with the help of dispersing agent polymer mentioned above. In the oil in water in oil type emulsion the dispersion of drug content is very difficult but it is easily produced by using polymer as a dispersing agent.

Film Coatings of Solid Dosage Forms
Chitosan's film forming abilities lend itself well as a coating agent for conventional solid dosage forms such as tablets. Furthermore its gel- and matrix-forming abilities make it useful for solid dosage forms, such as granules, micro particles, etc. Sakkinen and coworkers studied microcrystalline chitosan as gel-forming excipients for matrix-type drug granules. Crystallinity, molecular weight, and degree of deacetylation were seen to be factors that affected the release rates from the chitosan-based granules. Combination of positively charged chitosan with negatively charged biomolecules, such as gelatin, alginic acid, and hyalouronic acid, has been tested to yield novel matrices with unique characteristics for controlled release of drugs

Taste masked by spray drying:
Chitosan and drug are dissolved in suitable solvent. Sonication done by ultracentrifuge, after stirring 24 hrs with magnetic stirrer, after completely loading drug to polymer, complex dried by spray drying and evaluated for taste masking, Threshold concentration of bitterness. Complexes characterization done with the help of XRPD, FT-IR, DSC and SEM. If Complexation was achieve, % of drug content was determine and equivalent weight of complexes taken and formulate it. Dissolution of the chitosan – drug complexes tablet give sustain released effect.

Transdermal Drug Delivery Systems (Patches)
In the formulation of Transdermal Patches various polymer are used. The baking material also prepared from the polymer for supporting of drug in drug reservoir.

NOW YOU CAN ALSO PUBLISH YOUR ARTICLE ONLINE.

SUBMIT YOUR ARTICLE/PROJECT AT articles@pharmatutor.org

Subscribe to Pharmatutor Alerts by Email

FIND OUT MORE ARTICLES AT OUR DATABASE


Pages

FIND MORE ARTICLES