Capsule Dosage Form Lab (5) By: Shahen S. Mohammed MSc Pharmaceutics

Definition Capsules are solid dosage forms in which the drug substance is enclosed in water soluble shell or an envelope. The shells are generally formed from gelatin

Advantages Capsules are tasteless, odorless and easily can administered. Capsules are attractive in appearance. The drug having unpleasant taste and odor are enclosed in a tasteless shell. They can be filled quickly. They are economical. They are easy to handle and carry. The stability of therapeutic agents may be improved in a capsule formulation

Disadvantages Hygroscopic drugs are not suitable for filling into capsules, because they absorb water present in capsule shell makes shell very brittle and ultimately lead to crumble into pieces.

Capsules types Capsules may be classified depending on the nature of shell Hard gelatin capsules (two pieces) 2. Soft gelatin capsules (one piece)

The empty capsules are available in various sizes, they are numbered according to the capacity of the capsules, the numbers started from 000 and goes to up 5.

Differences between hard and soft gelatin capsules Hard gelatin capsule Soft gelatin capsule 1. Two pieces 1. One piece 2. Cylindrical shape 2. Available in round, oval and tube like shapes 3. Powder and solid material are encapsulated 3. Liquid and semi liquid are encapsulated 4. Gelatin in hard form is used 4. Molten gelatin are used 5. 8 different type of sizes are available 5. No specific sizes are available

Nature of the capsule shell Gelatin Water Plasticizer Miscellaneous

Gelatin Gelatin is heterogeneous product drived by hydrolytic extraction of animal’s collagen. The source of gelatin include animal bones and pork skin.

Water Water; Water is required both during the manufacturing process (to facilitate manufacture) and in the finished product to ensure that the capsule is flexible. Hot, demineralized water is used.

Plasticizer The plasticizer used are glycerin, sorbitol, etc.. The concentration of plasticiser is generally 20–30% w/w of the wet mass Concentrations in excess of 30% w/w will result in the capsule being too flexible and tacky whereas capsules in which the concentration of plasticiser is below 20% w/w will be too brittle.

Miscellaneous As is the case for hard gelatin capsules, soft gelatin capsules may be coloured or opaque, the chosen colour(s)/opacifiers being added during the manufacturing process. Titanium dioxide is primarily used as an opacifier for capsules. Opacifying agent may be used to provide protection against light. In addition, if required, flavouring agents may be added to the capsule shell.

Capsule sealing

Capsule filling machine

Filling of hard gelatin capsules Rectification Separating the caps from empty capsules Filling the bodies Scraping the excess powder Replacing the caps Sealing the capsules Cleaning the outside of the filled capsule

Evaluation of capsules Weight variation test Content uniformity test Dissolution test Disintegration test

Experiment