Sterile Pharmaceutical Dosage Forms - Parenteral Preparations

Introduction

Parenteral preparations are sterile products those are administrated by injection into the body. They may be directly administrated or they may be diluted before administration.

Production of Parenteral Products

Parenteral preparations are prepared by the methods that maintain their sterility, avoid the introduction contaminants and microbial growth.

The Parenteral preparations those are in the form of liquids require the base to dissolve them. Water for Injection is commonly used in Parenteral preparations. Any other suitable base may be used provided they are safe in the volume of injections administered and also do not interfere with the therapeutic efficacy of the preparation or with its response to the prescribed tests and assays of the Pharmacopoeia. 

Other auxiliary substances may be added to increase the stability and usefulness of the preparation. Those substances at the added concentration they should not have any adverse effect or cause toxicity. No coloring agent may be added to the Parenteral preparation for the purpose of coloring.

Parenteral preparations which are packaged in multiple-dose containers may contain suitable antimicrobial preservatives in the appropriate concentration to inhibit the microbial growth in the containers. The preservative effectiveness should be demonstrated before the production of Parenteral preparation.

When the active ingredients have the chances of oxidative degradation, a suitable antioxidant may be added and/or the air in the container may be evacuated or displaced by nitrogen or other suitable inert gas.

Also see: Media Fill Validation Test in Sterile Pharmaceuticals

Containers

Containers for Parenteral preparations should be made from materials that are transparent to permit visual inspection of the contents of the containers and should not adversely affect the quality of the preparation under the storage conditions, handling and use. These may be packed in glass ampules vials or bottles or in other containers such as plastic bottles.

Closures

Vials or bottles are closed with closures that are having a good seal to prevent the access of micro-organisms and other contaminants and a part or the whole of the contents of the container can be withdrawn without removal of the closure. The material of which the closure is composed must be compatible with the preparation and must allow the passage of a needle with the minimal shedding of particles and to ensure that the hole is resealed when the needle is removed.

Inspection

According to Good Manufacturing Practices, each final container of a Parenteral preparation must be individually inspected for visible foreign material. If any foreign material is found, the container should be rejected.

Labelling

The labeling of the containers of Parenteral preparations should be done in a manner that the area should be uncovered to inspect the content of the container. The label of any Parenteral preparation should contain the name of preparation, amount of active ingredient, storage conditions and the amount of diluent to be used to get the specified concentration of the active ingredient.

There are main following five types of Parenteral preparations:

1.  Injections

2.  Powders for Injection

3.  Infusions

4.  Concentrated Solutions for Injection

5.  Implants

1. Injections

Injections are sterile solutions those are prepared by dissolving the active ingredients and any added substances in Water for Injection or in a suitable non-aqueous base, or in a mixture of both if they are miscible.

Injections that are suspensions may show sediment but should be readily dispersible on shaking. The suspension should remain stable to deliver a homogenous dose of each withdrawal from the container.

2. Infusions

Infusions are sterile aqueous solutions with water as the continuous phase. They are free from pyrogens or bacterial endotoxins, are usually made isotonic with blood and do not contain any added antimicrobial preservatives.

3. Powders for injection

Powders for injection are sterile solid substances those are distributed in their final volume when shaken with the appropriate volume of sterile WFI to form a clear particle-free solution.

Also see: Lyophilization of Parenteral Pharmaceutical Products

4. Concentrated Solutions for injection

Concentrated Solutions for injection are sterile solutions that are administered by injection or by intravenous infusion only after dilution with water for injection.

5. Implants

Implants are sterile solid preparations of size and shape suitable for implantation into tissues to release the active ingredient for a long time period. They are filled individually in sterile containers.