Capsule (pharmacy)

Capsule (pharmacy)

In the manufacture of pharmaceuticals, encapsulation refers to a range of techniques used to enclose medicines in a relatively stable shell known as a capsule, allowing them to, for example, be taken orally or be used as suppositories. The two main types of capsules are:

  • Hard-shelled capsules, which are normally used for dry, powdered ingredients or miniature pellets (also called spheroids that are made by the process of Extrusion and Spheronization - Spheronization is a trade mark of Caleva Process Solutions) or tablets;
  • Soft-shelled capsules, primarily used for oils and for active ingredients that are dissolved or suspended in oil.

Both of these classes of capsules are made from aqueous solutions of gelling agents like:

Other ingredients can be added to the gelling agent solution like plasticizers such as glycerin and/or sorbitol to decrease the capsule's hardness, coloring agents, preservatives, disintegrants, lubricants and surface treatment.

Since their inception, capsules have been viewed by consumers as the most efficient method of taking medication. For this reason, producers of drugs such as OTC analgesics wanting to emphasize the strength of their product developed the "caplet" or "capsule-shaped tablet" in order to tie this positive association to more efficiently-produced tablet pills. After the 1982 Tylenol tampering murders, capsules experienced a minor fall in popularity as tablets were seen as more resistant to tampering.[1]

Contents

Single-piece gel encapsulation

Cod liver oil soft gel capsules.

In 1834, Mothes and Dublanc were granted a patent for a method to produce a single-piece gelatin capsule that was sealed with a drop of gelatin solution. They used individual iron moulds for their process, filling the capsules individually with a medicine dropper. Later on, methods were developed that used sets of plates with pockets to form the capsules. Although some companies still use this method, the equipment is not produced commercially any more. All modern soft-gel encapsulation uses variations of a process developed by R.P. Scherer in 1933. His innovation was to use a rotary die to produce the capsules, with the filling taking place by blow molding. This method reduced wastage, and was the first process to yield capsules with highly repeatable dosage.

The current owner of the RPScherer technology is Catalent Pharma Solutions, the world's largest manufacturer of prescription pharmaceutical softgels.

Softgels can be an effective delivery system for oral drugs, especially poorly soluble drugs. This is because the fill can contain liquid ingredients that help increase solubility or permeability of the drug across the membranes in the body. Liquid ingredients are difficult to include in any other solid dosage form such as a tablet. Softgels are also highly suited to potent drugs (for example, where the dose is <100 ug), where the highly reproducible filling process helps ensure each softgel has the same drug content, and because the operators are not exposed to any drug dust during the manufacturing process.

In 1949, the Lederle Laboratories division of the American Cyanamid Company developed the "Accogel" process, allowing powders to be accurately filled into soft gelatin capsules.

Two-piece gel encapsulation

Two-piece, hard starch capsules
Reconstruction from µCT-data of a hard starch capsule containing Diclofenac. Resolution 18,6 µm/pixel. Image acquisition was done using "CT Alpha" by "Procon X-Ray GmbH" from Garbsen, Germany. Analysis done using "VG Studio Max 2.0" by Volume Graphics, Heidelberg, Germany
Flight through the image stack of the above scan.

James Murdock of London patented the two-piece telescoping gelatin capsule in 1847.[2] The capsules are made in two parts by dipping metal pins in the gelling agent solution. Two-piece gelatin capsule machinery is manufactured by R&J Engineering Corporation of Canada. The capsules are supplied as closed units to the pharmaceutical manufacturer. Before use, the two halves are separated, the capsule is filled with powder or more normally spheroids made by the process of spheronization (either by placing a compressed slug of powder into one half of the capsule, or by filling one half of the capsule with loose powder) and the other half of the capsule is pressed on. With the compressed slug method, weight varies less between capsules. However, the machinery required to manufacture them is more complex.[3]

The powder or spheroids inside the capsule contains the active ingredient(s) and any excipients, such as binders, disintegrants, fillers, glidant, and preservatives.

Manufacturing materials

Gelatin capsules, informally called gel caps or gelcaps, are composed of gelatin manufactured from the collagen of animal skin or bone. (Gelatin is not derivable from ungulate hooves, which are composed of a different protein, keratin.)

Vegetable capsules are composed of hypromellose, a polymer formulated from cellulose.

Standard sizes of two-piece capsules

Size Volume (ml)[A] Locked length (mm)[A] External diameter (mm)[A]
5 0.13 11.1 4.91
4 0.21 14.3 5.31
3 0.3 15.9 5.82
2 0.37 18 6.35
1 0.5 19.4 6.91
0 0.68 21.7 7.65
0E 0.7 23.1 7.65
00 0.95 23.3 8.53
000 1.37 26.14 9.91
13 3.2 30 15.3
12 5 40.5 15.3
12el 7.5 57 15.5
11 10 47.5 20.9
10 18 64 23.4
7 24 78 23.4
Su07 28 88.5 23.4
A Approximate

Notes

  1. ^ Sims, Calvin (1986-02-15). "Despite "mystique" of capsules, many drugs work in other forms". New York Times. http://query.nytimes.com/gst/fullpage.html?sec=health&res=9A0DE1D71F3BF936A25751C0A960948260. 
  2. ^ "History of dosage forms and basic preparations". Encyclopedia of Pharmaceutical Technology. 7. Informa Health Care. 1998. pp. 304–306. ISBN 0-8247-2806-8. 
  3. ^ Bill Bennett and Graham Cole (2003). Pharmaceutical Production, an Engineering Guide. IChemE. pp. 126–129. ISBN 0852954409. 

References

  • L. Lachman, H.A. Lieberman, J.L. Kanig (1986). The Theory and Practice of Industrial Pharmacy (Third ed.). Lea & Febiger, Philadelphia. ISBN 0-8121-0977-5. 

See also



Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Capsule — The word capsule, or encapsulation, may refer to:* Capsule (anatomy), a cover or envelope partly or wholly surrounding a structure. * Capsule (fruit), a type of dry fruit like the poppy, iris or foxgloveVerify source|date=September 2007. *… …   Wikipedia

  • Capsule — has many meanings in medicine including the following: {{}}In medicine, a membranous structure that envelops an organ, a joint, tumor, or any other part of the body. It is usually made up of dense collagen containing connective tissue. In… …   Medical dictionary

  • Pharmaceutical formulation — Pharmaceutical formulation, in pharmaceutics, is the process in which different chemical substances, including the active drug, are combined to produce a final medicinal product. Contents 1 Stages and timeline 2 Oral formulations 2.1 Tablet form …   Wikipedia

  • Encapsulation — Wiktionarypar|encapsulationEncapsulation may refer to: * molecular encapsulation, in chemistry, the confinement of an individual molecule within a larger molecule * encapsulation (networking), in computer networking, to include data from an upper …   Wikipedia

  • Softgel — A softgel is an oral dosage form for medicine similar to capsules. They are a soft gelatin shell surrounding a liquid fill. Softgel shells are a combination of gelatin, water, and glycerin.Softgels are produced in a process known as encapsulation …   Wikipedia

  • Oblaat — (Japanese: オブラート) is a thin edible layer of starch that wraps some candies in Japan.[1] It is useful to preserve gelatinous sweets by absorbing humidity. It has no taste nor odor, and is transparent. The name comes from the Dutch language oblaat …   Wikipedia

  • pharmaceutical industry — Producers of pharmaceuticals, substances used in the diagnosis, treatment, and prevention of disease and the modification of organic functions. The earliest records of medicinal plants and minerals are those of the ancient Chinese, Hindu, and… …   Universalium

  • University of Saskatchewan Academics — University of Saskatchewan has over 200 academic programs on its Saskatoon, Saskatchewan campus. The U of S is internationally known for its teaching and research. The Canadian Light Source and Synchotron is the only such Canadian institution for …   Wikipedia

  • Eckerd Corporation — Infobox Defunct Company company name = Eckerd Corporation company former type = Pharmacy foundation = 1898 defunct = 2007 fate = Acquired by Rite Aid location = Warwick, Rhode Island products = Pharmacy, Liquor, Cosmetics, Health and Beauty Aids …   Wikipedia

  • Pharmaceutical drug — Medication redirects here. For other uses, see Medication (disambiguation). Medicines redirects here. For other uses, see Medicine (disambiguation). A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”