Gelatin has a long and varied history in medicine, going back as far as 1834. Nowadays, it is a common material used in a number of pharmaceutical and biomedical applications around the world. With its well-established versatility and reliability, it is no surprise gelatin is now playing an important role in groundbreaking regenerative medicine where, for example, it is used to produce hydrogels that support cell growth.
This article outlines key moments in gelatin’s pharma-medical history and takes a look at how it’s used in pharma and medical applications.
What is gelatin?
Gelatin is a protein derived from animal raw materials. It is obtained by partial hydrolysis of collagen, the most abundant protein in the animal world, with high concentrations present in connective tissues. It consists of eighteen amino acids, eight of which are considered essential. As a polydisperse polymer, gelatin exhibits many useful properties and functions that lend themselves to pharmaceutical and medical applications.
Properties
- Safe
- Soluble
- Thermoreversible
- Digestible
- Biocompatible
- Odorless / flavorless
- Low allergenic potential
Functions
- Water-binding
- Gelling
- Strengthening / stabilizing
- Film forming
- Adhesion
- Soluble
- Thermo-reversible
- Foaming
The history of gelatin in pharmaceutical and medical applications
Gelatin capsules
1834
The gelatin capsule was invented in 1834 by François Mothes(1), a young pharmacist in France. At the time, doctors had trouble getting patients to comply with taking medicines because most medicine came in a foul-tasting liquid or powder form. Another problem was getting the measurements right for each dose. So Mothes came up with a method to encapsulate an exact dose of liquid medicine in a thin coating of hot liquid gelatin that hardened upon cooling. When filled with medicine, the capsule could be swallowed without being tasted and dissolved at body temperature releasing the active ingredient.1847
The gelatin capsule quickly caught on around the world. In 1847, the first two-piece gelatin hard capsule was invented by James Murdock, a London based inventor(2). This development allowed drugmakers to encapsulate powdered forms of medicine.1894-1897
By the end of the 19th century, America had become the world leader in the development of gelatin capsules(3). Between 1894-1897, American pharmaceutical company Eli Lilly built the first-ever capsule manufacturing plant for the production of newly developed two-piece, self-locking hard capsule.1930
Robert P. Scherer revolutionized the production of soft gelatin capsules (softgels) by developing an automatic, continuous filling machine that made mass production possible(4). Today, gelatin is a widely used excipient for hard capsules and softgels.Gelatin-based plasma substitutes
1915
Plasma substitutes are a colloidal solution used to replace blood volume and restore blood pressure during medical emergencies.
In 1915, Dr. James Logan was the first person to successfully administer a gelatin-based plasma substitute intravenously(5). This development went relatively unnoticed in the interwar period, during which other colloidal solutions, such as gum arabic, were used. These non-gelatin colloidal solutions were effective as volume expanders and posed less risk to patients.
1940-1952
The development of gelatin-based plasma substitutes was not picked up again until World War II. Several clinical trials in the 1940s showed gelatin had the potential to be an effective plasma substitute, much safer than other colloidal solutions. This potential was realized in 1952 when succinylated gelatin, a new generation of chemically modified gelatin, was invented.
1962
Later, the development of succinylated gelatin enabled scientists to create a finely tuned gelatin, high in molecular weight and low in viscosity, making it ideal for plasma substitutes. In 1962, came the development of urea-linked gelatin from a chemical modification that involves the cross-linking of polypeptides(6).
Today
Plasma substitutes prepared from succinylated gelatin and urea-linked gelatin are commonly used today.
Gelatin-based hemostats
1940
The word "hemostat" is derived from "hemostasis," the biological process of stopping and preventing bleeding. A hemostat is a medical device used by surgeons to stop bleeding and facilitate healing during and after surgical procedures. The first gelatin-based hemostats were developed in the 1940s. Until then, hemostats were made from a combination of human plasma and bovine thrombin, both of which were difficult to purify. This lack of purity increased the risk of infection for patients. Scientists began using novel gelatin-based hemostatic agents to create hemostats. Gelatin was an excellent choice because it has the right functional and physical properties and offers higher levels of purity, improving patient safety(7).
Today
Gelatin-based hemostats are now a standard part of surgeons toolkits.
How gelatin is used in pharmaceutical applications
Hard capsules and softgels
Gelatin is used as an excipient in the production of hard capsules and softgels. It has lower production costs, fewer manufacturing complexities and secures excellent active pharmaceutical ingredient (API) dissolution rates. It also helps protect sensitive ingredients from oxygen, light, microbial growth and other forms of contamination.
Pharmaceutical gelatin offers several technical advantages over non-gelatin excipients, such as hydroxypropl methylcellulose (HMPC) for hard capsules and modified starch for softgels. Additionally, it is the only excipient without an Enumber, making it a natural ingredient under the ISO technical specification on definitions and technical criteria (ISO/TS 19657:2017).
Tablets
Two types of gelatin are commonly used as binders in tablets:
- Non-gelling
- Gelling
Gelling gelatin is used after granulation of the tablet powder in compression. It has a higher gel strength, which provides cohesiveness, resistance and hardness to the tablets. Its high gel strength also results in a longer disintegration rate.
Non-gelling gelatin is used in direct compression. It has lower binding power, making the tablets weaker. However, it has a fast disintegration rate, allowing patients to experience the effects of the medicine more quickly.
Blood plasma substitutes
Hydrolyzed gelatin is an important component of plasma substitutes, a class of parenteral formulation known as volume expander. When highly purified with low endotoxin level, it can be used to temporarily expand blood volume during medical emergencies.
It is the ideal ingredient because it is:
- Highly biocompatible
- Similar in viscosity and molecular behavior to blood plasma
- Short in retention time, especially when compared to starch alternatives
- Biodegradable and does not accumulate in the body
- Stable throughout the product's lifecycle
The hydrolyzed gelatin used in plasma substitutes requires special modification. There are two main types of modified gelatin used in plasma substitutes:
Succinylated gelatin is the most common type, offering improved body compatibility.
Urea-linked gelatin is modified by cross-linking polypeptides, resulting in a slower diffusion rate.
Vaccines
A specially purified gelatin with low endotoxin levels is used as a stabilizer in some vaccines. It provides the following benefits:
- Helps maintain the stability of lyophilized (freeze-dried) products
- Reduces potential for side effects
- Ensures patient safety
How gelatin is used in medical devices
Gelatin-based hemostats
Gelatin is a widely used hemostatic agent that helps surgeons minimize blood loss during surgery. Gelatin-based hemostats are typically made from porcine collagen (sourced from pork skin) and are available in sponges, strips, powder or nanofibers.
Gelatin-based hemostats can absorb more than 40 times their own weight, making them ideal for creating artificial blood clots and stopping blood flow. When combined with thrombin, they can further aid in clot formation.
Because gelatin is highly biocompatible, gelatin sponges can be left in the body to naturally dissolve. Some in vivo applications require specific dissolution rates, allowing the sponges to be specifically configured to meet individual needs.
Femoral plugs
Femoral plugs are a device used in hip replacements. Purified gelatin, combined with plasticizer for increased elasticity, can be used in femoral plugs. These plugs facilitate the change of prothesis and protect tissues from exothermic reactions during plaster setting. With high biocompatibility, low immunogenicity and high biodegradability, they can be absorbed by the body.
How gelatin is used in regenerative medicine
Regenerative medicine combines molecular biology and tissue engineering, aiming is to use a patient’s own cells to repair and regenerate diseased or injured tissue.
In this field, gelatin is a useful biomaterial that mimics the extracellular matrix and promotes cell growth, improving cell viability. The gelatin used in regenerative medicine must be highly purified to minimize endotoxins and pyrogens, ensuring optimal performance and patient safety.
What is pharma-medical grade gelatin?
Gelatin is a soluble protein obtained by the partial hydrolysis of collagen derived from the bones, hides and skins of animals primarily cows, pigs and fish. To extract gelatin, native collagen is rendered soluble via acid, alkaline or enzymatic treatment and then boiled in water. For gelatin to be considered pharmaceutical-grade, it must meet certain standards:
Quality control and traceability
Testing, control and full traceability are important. This includes careful selection of raw materials and suppliers, swift collection and transport, and strict testing and control of raw materials to ensure optimal quality and safety.
Technical specifications
Gelatin has to meet the specifications described in the pharmacopeia, including:
- Gel strength range
- pH range
- Conductivity
- Loss on drying
- Zinc content
GMP Compliance
Gelatin must be produced in alignment with good manufacturing practices (GMP) suitable for its intended application, such as excipient, raw material for medical devices, tissue engineering, etc. The process is audited by pharmaceutical companies.
We help customers to abide by regulations and guidelines worldwide.
Special adaptations
Raw materials for medical devices and other specific applications (such as parenteral, regenerative medicine and cell culture) may have additional requirements depending on the final application, including virus inactivation studies and being free of endotoxins, pyrogens and mycoplasma.
Reasons why gelatin is used
Gelatin is a polydisperse polymer with a unique set of functionalities and properties that make it suitable for a wide range of applications.
The main properties of gelatin:
Thermo-reversible
Gelling-grade gelatin is thermoreversible, meaning it has the ability to melt and set reversibly at a temperature between 25°C and 32°C (gelatin solution at 10%). The exact transition temperature depends on the type and concentration of gelatin used, making it a versatile material for applications requiring different melting temperatures.
Bloom (Gel strength)
The bloom value of gelling-grade gelatin determines the firmness of gelled products. Hydrolyzed gelatin has no gel-forming capability, so its bloom value is 0.
Biocompatibility
As a natural protein, gelatin offers high biocompatibility and is well-tolerated by the human body.
Body temperature melting point
Gelatin melts at body temperature, making it ideal for pharma-medical applications that require metabolization.
Other reasons:
Clean label friendly
There is an increasing demand for products made with safe, natural-origin materials. Additionally there is a broader push to enhance patient safety. Gelatin meets both of these needs.
Natural origin(8)
Gelatin is a naturally occurring protein extracted from animal collagen.
Safe
Gelatin is considered non-allergenic, except in rare cases of meat allergy. It is also Generally Recognized As Safe (GRAS) by the FDA.
Quality Control
Gelatin is a stable and safe excipient with excellent physical and chemical properties. The production process follows stringent national and international pharmaceutical processing requirements.
"Whatever the future holds, we are certain gelatin will play a key role."
In conclusion
With a history spanning nearly two centuries, gelatin has played a crucial role in the evolution of pharmaceuticals and medicine. Consider the lives saved by plasma substitutes and hemostats. Today, we often take these medical devices for granted, but at one point, they had to be invented and improved - gelatin made that possible.
Looking to the future, gelatin will remain an essential part of medical innovation. Medical technologies that once existed only in the realm of science fiction are now becoming reality. The future holds many exciting developments, especially in regenerative medicine, where scientists are learning how to grow cells and repair bodily organs. Who knows - one day, gelatin could play a role in growing new organs from your own DNA!
Contact our team today to customize pharmaceutical-grade gelatins to exact specifications!
- Pharmaceutical Capsules (2nd ed., p.2)
- Modern Pharmaceutics (4th ed. p.513)
- Pharmaceutical Capsules (2nd ed., p.11)
- Traveling Through Time: A Guide to Michigan's Historical Markers (p.483)
- https://jamanetwork.com/journals/jama/article-abstract/440081
- https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2044.1987.tb05376.x
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2978438/
- Gelatin is considered as a natural ingredient in accordance with the ISO technical specification on definitions and technical criteria (ISO/TS 19657:2017).