Gelatin: A Widely Used Pharmaceutical Excipient

            Roshani K. Mahajan*, Priyanka B. Saindane, Dr. Ravindra S. Sonawane,

Mr. Devesh P. Bhavsar 

KES’s Late Shri P.C.Bhandarkar College of D.Pharmacy & Late Shri Prof.  R. K. Kele College of

B. Pharmacy, Amalner. Dist-Jalgaon,

*Correspondence: mahajanroshani08@gmail.com;

DOI: https://doi.org/10.71431/IJRPAS.2025.41214    

INTRODUCTION

Gelatin is a colorless or pale yellow, transparent sheets, flakes, shreds or course of fine powder which is partial hydrolysis of collagen [1]. Gelatin constitutes 25.5% oxygen, 0.8% hydrogen, 50.5% carbon & 17% nitrogen & it also has a mixture of single & double unfolded chains of hydrophilic characters [3]. Gelatin is also used as encapsulating agent, suspending agent, tablet binder & coating agent. In dry condition, gelatin is stable whereas, In moist atmosphere there is a high risk of microbial contamination [1]. Gelatin is applied for microencapsulation of drugs, perfumes, flavors & some industrial products. It is also employed as a vehicle for various injections such as heparin in the form of Pitkin’s which constitutes gelatin, dextrose, acetic acid & water. It is also used in cultivation of bacteria, absorbable gelatin sponge & gelatin film [5]. Soft gelatin capsule is a unit solid dosage form containing a liquid or semi-solid in it. Soft gel capsules are used in the pharmaceutical, chemical, food & cosmetic industries [2]. Soft gelatin capsule manufacturing machine is invented in 1970. The production rate of soft gelatin capsule is up to 60 billion pills/year in the world [4].

Gelatin has introduced to us since very ancient times : 10^th century B.C. the book “Kitab-al-Tabikh” gives the preparation method for fish jelly which is derived by the boiling of fish head [5,6]. “Viandier of Taillevent” ,the book which included the process for preparing a jellied meat broth, through which gelatin also prepared. In the 15^th century, in Britain the waste of meat and cattle hooves used as a row material for production of gelatin [7]. In 1681, the French scientist Denis Papin has been introducing a new method for extraction of gelatin by boiling the bones [8]. A French researcher Jean-Pierre-Joseph d’Arcet, In 1812 modified the experiment of his predecessor by introducing hydrochloric acid in the process of extraction of gelatin from bones in combination with steam extraction which results in increasing its efficiency. The French government considers the gelatin has major source of inexpensive and affordable protein for the poorest society [9]. In USA gelatin gained particular popularity in food products named as jell-O [10] . From 19^th century gelatin has been available in powder form and sold on large scale [11]. Nowadays, gelatin is the most demanding gelling agent in the food and pharmaceutical industries. There are varieties of gelatin used in pharmaceutical and non pharmaceutical product preparations. Various food product such as dessert , trifles, aspic, marshmallows, candy corn, and confections such as peeps gummy bears, fruit snacks, and jelly babies. Other uses of gelatin as a stabilizer, thickener, or texturizer in products such as yoghurt, cream cheese, and  margarine [12].

The main precursor of gelatin is collagen. On the hydrolysis of collagen we get various molecular weights, but each of them is a fragment of the collagen chain. So, it is concluded that gelatin is not a single chemical compound but a mixture of various amino acids  bonded together  by peptide bonds  to give a low molecular weight  polypeptides having general formula and molecular mass[M]  from 15,000 [13,14] and above or their aggregates with M=200.000 -300.000 [15,16], which is made up of 18 natural amino acids out of 20, except cystine and cysteine . so due to its high M values it is known as biopolymer .  but only the synthetic and natural high molecular compounds considered as polymers, in which repeating  structural units are present. More than 100 years ago, the quantitative analysis of gelatin has been studied [17]. From this given data the chemical elements which  constituent’s  gelatin  are : C-50.5, H-6.8, N-17.0 and O-25.2(in wt.%). 

Fig. 1. Amino Acid Composition of Gelatin.

In the middle of the 20^th century, the composition of amino acid present in gelatin was already studied [18,19,20,and 21]. It concluded that the predominant part of the amino acid is the residue of amino acid known as glycine. Gelatin contains high amount of the cyclic amino acid proline and hydroxyproline which make it different from other proteins [22].

In 1685, Holland has been commercially manufacture gelatin and then in England in 1700. The United States also established first commercial production of gelatin was in Massachusetts in 1808 [23].

SYNONYMS

Gelatina, Gel foam, Puragel, Hydrolyzed collagen, etc.

TYPES

Type A: Type a gelatin is derived from pigs, poultry, and fishes.

 Type B: Type B gelatin is derived from bovine sources

PHYSICOCHEMICAL PROPERTIES

SYNTHESIS OF GELATIN

There various types of Gelatin on the basis of their source. However their synthesis method also varies.

From Fish skin :

Pretreatment fish skin

Cut into pieces

Soaked in 20 times 0.01 M NaoH containing 1% H2O2 at 4⁰C for 24 hours

Defatted in 20 times 10% isopropanol at 4⁰C for 4 hours

Swelled with 20 times 0.05 M acetic acid at 4⁰C for 4 hours

Extracted with 10 times distilled water at 45⁰C for 10 hours

Centrifuged at 18,000xg for 20 minutes at 10⁰C

Supernatant (Gelatin)

Freeze-dried

Gelatin powder

Fig. 2. Synthesis of Gelatin from Fish skin [24].

From Bones:

Dry bones

Crushing

Treatment with HCL 4-7%, 10-14 days

Dicalcium phosphate

Ossein

Lime 5-15%, 3-8 weeks

Wash

Lime removal

pH adjustment (sour) HCL, H2SO3, H3PO4 or H2SO4

Extraction

Filtration

Concentration (12-25%)

Drying (32-60⁰C, humidity control)

Crushing

Type B gelatin

Fig. 3.Synthesis of Gelatin from Bones

USES OF GELATIN

Gelatin is worldwide used biotic product in various sectors such as:

Medicines:

•                     It is used as stabilizer in various vaccines

•                     Used in Production of shells of soft as well as hard gel capsules.

•                     It is used as vehicle for various semi-solid dosage forms.

Cosmetics:

•                     Gelatin is a hydrolyzed collagen used in topical preparations.

•                     Collagen implants or dermal fillers also used to reduce wrinkles

Culinary uses:

•                     It is used in purification of liquid beverages.

•                     Gelatin used in various food products such as dessert trifles, aspic, gummy bears, marshmallows & candy corn, etc

HANDLING PRECAUTIONS

•                     Do not use for drug, household or other purpose.

•                     Before handling consult safety data sheets to know about hazards & safe handling practices.

•                     Do not use during pregnancy and breast feeding

STORAGE:

•                     It must be stored in dry place below 30⁰C.

•                     Gelatin is humidity sensitive. So, it must be stored under relative humidity condition of 65%.

INCOMPATIBILITIES:

Incompatibilities occur when wide range of concentrations for mixtures prepared in deionized water & this is overcome by increasing pH or salt concentration.

Temperature also influencing with incompatibilities but at shorter range

ADVERSE EFFECTS:

•                     Sore throat

•                     Swollen gums

•                     Mouth sores

•                     Heaviness in Stomach

•                     Bloating

•                     Heartburn

EVALUATION:

•                     Assay: Assay is performed to check the protein content & proteolytic activity.

•                     pH: Between 4.8-5.5 .

•                     Loss on Drying: Performed at 105⁰C for about 16 hours.

•                     Ultraviolet Rays: Ultraviolet rays causes denaturation of proteins of gelatin which results in

            reduced bloom strength.

•                     Infrared Radiation: It causes change in structure of protein by disrupting the hydrogen bonds &

             leads to decrease gel strength.

MARKETED PRODUCTS:

CONCLUSION

Gelatin has established itself as one of the most versatile and indispensable excipients in the pharmaceutical industry. It’s unique physicochemical properties such as film‑forming ability, biodegradability, biocompatibility, and ease of processing makes it suitable for a wide range of applications, from hard and soft capsule shells to microencapsulation, tablet binding, and controlled drug delivery systems. Beyond its functional role, gelatin also contributes to patient compliance by enabling elegant dosage forms and improving stability of sensitive active ingredients. Despite the emergence of synthetic and plant‑based alternatives, gelatin continues to dominate due to its cost‑effectiveness, safety profile, and long history of regulatory acceptance. However, challenges such as allergenicity, religious restrictions, and the need for sustainable sourcing highlight areas where innovation and substitution may be required.

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