Minor Research Project Proposal (Interdisciplinary Project) for “Synthesis of starch based polymer/ copolymers for drug delivery application”.
Introduction:
The ways in which drugs or chemicals are administered have gained increasing attention in the past two decades. Normally, a drug is administered in a high dose at a given time only to have to repeat that dose several hours or days later. This is not economical and sometimes results in damaging side effects. As a consequence, increasing attention has been focused on methods of giving drugs continually for prolonged time periods and in a controlled fashion. The primary method of accomplishing this controlled release has been through incorporating the drugs within polymers. This technology now spans many fields and includes pharmaceutical, food and agricultural applications, pesticides, cosmetics, and household products.
Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. Drug delivery technologies modify drug release profile, absorption, distribution and elimination for the benefit of improving product efficacy and safety, as well as patient convenience and compliance. Drug release is from: diffusion, degradation, swelling, and affinity-based mechanisms. Most common routes of administration include the preferred non-invasive per oral (through the mouth), topical (skin), transmucosal (nasal, buccal/sublingual, vaginal, ocular and rectal) and inhalation routes.
Current efforts in the area of drug delivery include the development of targeted delivery in which the drug is only active in the target area of the body (for example, in cancerous tissues) and sustained release formulations in which the drug is released over a period of time in a controlled manner from a formulation. In order to achieve efficient targeted delivery, the designed system must avoid the host’s defense mechanisms and circulate to its intended site of action. Types of sustained release formulations include liposomes, drug loaded biodegradable microspheres and drug polymer conjugates
In recent years, considerable attention has been focused on the development of drug delivery systems. Different types of sustained drug delivery systems have been speculated for various routes of administration, as they require less frequent drug administration, it provide more efficient therapeutic effects and reduce the incidence of side effects.
Synthetic and natural-based polymers have found their way into the pharmaceutical and biomedical industries and their applications are growing at a fast pace. Understanding the role of polymers as ingredients in formulation of drug products is important for a pharmacist or chemist who deals with drug products on a routine basis. Having a basic understanding of polymers will give the opportunity to not only familiarize with the function of drug products but also possibly develop new formulations or better drug delivery systems.
In oral delivery, polymers are used as coatings, binders, taste makers, protective agents, drug carriers and release controlling agents. Targeted delivery to the lower part of the gastrointestinal tract (e.g., in the colon) was made possible by using polymers that protect drugs during their passage through the harsh environment of the stomach. Transdermal patches use polymer as backings, adhesives or drug carriers in matrix or membrane products. Controlled delivery of proteins and peptides has been made possible using biodegradable polymers. In many drug products we may find at least one polymer that enhances product performance. Polymeric nanoparticles consist of the drug dispersed in an amorphous form within a polymer matrix. Such particles could be prepared as nanospheres, wherein the drug is dispersed uniformely throughout the matrix of the particle (typically as a solid solution in polymer), or as nanocapsules, wherein the drug is present in the core of the particle.
Of the many materials used in the pharmaceutical formulations, polymers play the most important roles. The use of polymers ranges from manufacturing of various drug packaging materials to the development of dosage forms. The important application of polymers undoubtedly resides in the development of sophisticated controlled release drug delivery systems. In conventional dosage forms, polymers are usually used as excipients, adjuvants, suspending agents, or emulsifying agents. In controlled release dosage forms, polymers are used mainly to control the release rate of drugs from the dosage forms. The presence of numerous polymers which are able to control the drug release profiles has been the basis for the explosive advances in the development of controlled release dosage forms during 80’s. It would not be an overstatement that the future development of more sophisticated dosage forms entirely depends on the appropriate use of existing polymers and synthesis of new polymers.
Polymers are becoming increasingly important in the field of drug delivery. The pharmaceutical applications of polymers range from their use as binders in tablets to viscosity and flow controlling agents in liquids, suspensions and emulsions. Polymers can be used as film coatings to disguise the unpleasant taste of a drug, to enhance drug stability and to modify drug release characteristics.
The number of products based on new drug delivery systems has significantly increased in the past few years, and this growth is expected to continue in the near future. Recent advances in the field of genomics have accelerated research of biopharmaceuticals, and today a large number of companies are busy developing protein- and peptide-based drugs. These biopharmaceuticals present challenges to drug delivery scientists because of their unique nature and difficulty in delivery through conventional routes. Therefore, future research will focus on the delivery of these complex molecules through different routes, including oral, nasal, pulmonary, vaginal, rectal, etc. This work is to update/ modify some of the copolymers used in existing drug delivery technologies for oral controlled-release, delivery of large molecules, liposomes, taste masking, fast-dispersing dosage forms, and technology for insoluble drugs.
In the 21st century, the pharmaceutical industry is caught between the downward pressure on prices and the increasing cost of successful drug discovery and development. The average cost and time for the development of a new chemical entity are much higher (approximately $500 million and 10–12 years) than those required to develop a novel drug delivery system (NDDS) ($20–50 million and 3–4 years). In the form of an NDDS, an existing drug molecule can get a new life, thereby increasing its market value and competitiveness and extending patent life.
Limited formularies, patent expiry with subsequent entry of generic competition, and vertical integration have the entire pharmaceutical industry (approximately 350 drug delivery companies and 1000 medical device companies) focused on designing and developing new and better methods of drug delivery. There has been a significant increase in approvals of NDDSs in the past couple of years, and this is expected to continue at an impressive rate in the near future. The sale of drug delivery products is valued at more than $120 billion worldwide, and this growth is expected to continue into the present century. It is estimated that the drug delivery market will be at $250 billion by 2015.
Current status of drug delivery technologies
Incorporating an existing medicine into a new drug delivery system can significantly improve its performance in terms of efficacy, safety, and improved patient compliance. The need for delivering drugs to patients efficiently and with fewer side effects has prompted pharmaceutical companies to engage in the development of new drug delivery systems. Today, drug delivery companies are engaged in the development of multiple platform technologies for controlled release, delivery of large molecules, liposomes, taste-masking, oral fast dispersing dosage forms, technology for insoluble drugs, and delivery of drugs through intranasal, pulmonary, transdermal, vaginal, colon, and transmucosal routes. All these are with polymers. Various types of polymers and copolymers are developed and used for various dosage forms and drug delivery.
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Objective
Aim of the present project is to develop / modify starch based various copolymers and explore its application in drug delivery systems. The optimize formulation will be also subjected to in vitro study.
It’s an interdisciplinary project area where contribution of chemical engineering as well as pharmacy is required. It would be possible to test its applicability by conducting experiments in laboratories of Institute of pharmacy.
Scope of the research work
The specific research objectives are as follows: