VEGICAPS SOFT CAPSULES


Vegicaps soft capsule are an alternative animal free capsule. The shell is made from seaweed extract and gluten free starch and contains no modified sugars or artificial ingredients. The shell can be clear or colored and there is a wide range of shapes, sizes and colors available.
  • An alternative to gelatin for those who prefer an animal free product
  • Those with a level of concern about animal derived products
  • Vegetarians
  • Those with religious or cultural restrictions
  • Consumers looking for the most natural alternative

Dissolution Method of Soft Gel Capsule Dissolution


The bioavailability of the bio-actives in the soft gel depends on the dissolution of both its shell and fill. Dissolution of a chemical compound in the aqueous environment of the gastrointestinal tract is often the rate-limiting step in its absorption. If a substance, such as oil, is insoluble in the acidic solution of the gastrointestinal tract, then its dissolution can be slow. However, if this substance is administered in a vehicle in which it is soluble, then the absorption process may be enhanced.

Dissolution problems of the soft gel shell are less common; they may become apparent upon aging, which are attributed to the cross-linking of gelatin. The cross-linking causes the formation of a swollen, tough, rubbery, and water-insoluble material.

High humidity causes the capsules to become soft, tacky, and bloated and may increase the likelihood of moisture migration from the shell into the fill material. Such a transfer can cause chemical, physical and dissolution instability.

Extraction of Essential oils from Flowers Using Solvent Extraction Method


Extraction system is a manufacture of essential oils which raw material has a small yield, damaged at high temperatures, and mostly soluble in water. Extraction normally used for essential oils of flowers. Some commodities that use essential oils extraction systems include roses, jasmine, and evening primrose.

Extraction can be divided into three types :
  1. extraction with solvent evaporates
  2. extraction with cold fat
  3. extraction with hot fat
Commercial extraction of essential oils is generally performed with the solvent evaporated.

Principle with the solvent extraction method is to dissolve essential oils evaporate within the material of volatile organic solvents. Solvents which can be used include alcohol, hexane, benzene, and toluene. In addition, it can also use a non-polar solvents such as methanol, ethanol, chloroform, acetone, petroleum ether, and ethylacetate with high levels of 96%.

Compression Coating Tablet Manufacturing Method


Compression coating tablet is compressing a coat around a core using specially designed processes. The process involves preliminary compression of the core, which is then transferred to a large die already containing some (a half) coating material. After centralizing the core, further coating material is added and the whole compressed to form the compression-coated tablets.

There are two types of machine available for the preparation of press-coated tablet :
  1. core previously prepared on other machines
  2. compression of core and coat in one continuous circle 

Factors Affecting on Drug Release in Compression-Coated Tablet (Part II)

Tablet cores 

1. Drug solubility
Higher solubility drug containing cores in compression-coated tablets provided shorter lag time than lower solubility drug containing cores.

2. Tablet core formulation
Drug release from compression-coated tablet containing a fast release core was faster than extended release core containing coated tablet when the same coating composition was used. The release behavior and the lag time were dependent on the type of excipient used in the core.
The influence of different composition of cores on drug release from spray-dried chitosan acetate/ HPMC compression-coated tablets. Soluble diluent and appropriate amount of super disintegrant in core tablets enhanced drug release while osmotic agent slightly retarded drug release.
Formulation and compression-coating technique

Factors Affecting on Drug Release in Compression-Coated Tablet (Part I)

Compression coating 

1. Polymer type
The pharmaceutical polymers used (single or combination) in compression coating are :
  • cellulose derivatives (e.g. hydroxypropylmethylcellulose acetate succinate, ethylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose and hydroxyethylcellulose),
  • polysaccharides (e.g. guar gum, sodium alginate and pectin)
  • water soluble polymer (polyethylene oxide)
  • wax (behenic acid)
  • methacrylate copolymers 
The coats containing these polymers could be divided into groups such as :
  • water insoluble (ethylcellulose)
  • erodible (low molecular weight hydroxypropylmethylcellulose, hydroxypropylcellulose, polyethylene oxide)
  • gellable or swellable (high molecular weight hydroxypropylmethylcellulose)
  • pH dependent soluble (hydroxypropyl-methylcellulose acetate succinate, methacylic acid copolymer)
  • waxy
  • bacterial digestible.

Microbial Controlled Release : Mechanism of Action and Polysaccharide Excipients


A delayed release system may be aimed for colon drug targeting. The colon targeted delivery of pharmaceutical drugs is important to achieve localized effect for the treatment of colonic diseases and/or systemic drug delivery for drugs absorbed from colon, for e.g. peptides and proteins.

This system is based on the degradation of the polymeric compression-coat by specific enzymes produced by entero-bacteria in the colon. Importance of microbial polysaccharidases in colon specific drug delivery of formulations containing polysaccharide excipients is beyond doubt. Present review presents a compilation of the important polysaccharide excipients, along with their metabolism in human colon, the mechanism of action of the degrading enzymes and genetic aspects of polysaccharide degrading colonic microflora shall help in the improvement in the field of colon targeting.

Delayed Release Drug


Delayed release, defined with lag phase and followed with release phase, is obtained when all surface of core is compression-coated. Pulsatile release defined by fast drug release after a certain lag time could be categorized within this group as well.

Lag time for drug release could be controlled by the application of different polymeric coats which were differentiated with triggering factors to control drug release as mainly mentioned in colonic drug delivery system.

Enteric/delayed release coatings consist of pH sensitive polymers, which means the coating remains intact in the acidic environment of the stomach and then solubilizes in the more alkaline environment of the small intestine. Most enteric coatings work by presenting a surface that is stable at the highly acidic pH found in the stomach, but breaks down rapidly at a less acidic (relatively more basic) pH. For example, they will not dissolve in the acidic juices of the stomach (pH ~3), but they will in the alkaline (pH 7-9) environment present in the small intestine.

Mechanism Action of Plasticizers in Film Coating Tablet

The mechanism of action of plasticizers is defined as to interpose between every individual strand of polymer and thereby causing breakdown of polymer-polymer interactions. The tertiary structure of the polymer is modified into more porous, flexible and with less cohesive structure.


Plasticizers soften and swell the polymer which aids in overcoming their resistance to deformation. plasticized polymer would deform at a lower tensile force as compared to without plasticizer. This enhances the polymer – plasticizer interaction. This effect in turn enhances the film elongation effect.

The interaction to a greater extend depends upon the glass transition temperature of polymers. Glass transition temperature. Tg is the temperature at which hard glassy polymer is converted into a rubbery material.


CURING CONDITIONS – Thermal Treatment After Tablet Coating Process


What is Curing condition in coating tablet process? Curing is as thermal treatment following the application of coat.

The coalescence of colloidal polymer particles from the aqueous coating dispersions is usually incomplete. As a result coalescence of particles during the storage temperature and time can occur which can in turn modify the release of drug from the coated products

CLASSIFICATION OF PLASTICIZERS

Depending on their properties plasticizers can be classified as :
1. Polyols
  • Glycerol
  • Propylene glycol
  • PEG 200-6000 grades
2. Organic esters
  • Triacetin
  • Diethyl phthalate (DEP)
  • Dibutyl phthalate (DEB)
  • Tributyl citrate (TBC)

PLASTICIZER EFFECT IN FILM COATING TABLET


Plasticizers are generally non-volatile, high boiling, non-separating substances. Plasticizers used in a polymeric system should be miscible with the polymer and exhibit little tendency for migration, exudation, evaporation, or volatilization. Many compounds can be used to plasticize polymers. Phthalate esters such as diethyl phthalate, sebacate esters such as dibutyl sebacate, and  citrate esters such as triethyl citrate and tributyl citrate are commonly used as plasticizers. Various glycol  derivatives including propylene glycol and polyethylene glycol have also been  used to plasticize polymeric films. 

Effect of Plasticizers on Mechanical Properties of Films
  • Decrease in tensile strength. Ultimate tensile strength (UTS), often shortened to tensile strength (TS) or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract. Tensile strength is the opposite of compressive strength and the values can be quite different.
  • Decrease in elastic modulus. An elastic modulus, or modulus of elasticity, is the mathematical description of an object or substance's tendency to be deformed elastically (i.e., non-permanently) when a force is applied to it.
  • Increase in film elongation
  • E.g. the effect of plasticizers on the mechanical properties of cast film of H P MC i.e.; Methocel ES was studied and it was found that the low molecular weight PEGs had a better plasticizing effect as compared to higher molecular weight due to viscoelastic effect of former.

Technology of Liposomes Production (PART I)

Conventional method for Liposome Production

Phospholipids are dissolved in an organic solvent (used a chloroform/methanol mixture) and deposited from the solvents as a thin film on the wall of a round bottom flask by use of rotary evaporation under reduced pressure. MLVs form spontaneously when an excess volume of aqueous buffer containing the drug is added to the dried lipid film. Drug containing liposomes can be separated from non-sequestered drug by centrifugation of the liposomes or by gel filtration. The time allowed for hydration of the dried film and conditions of agitation are critical in determining the amount of the aqueous buffer (or drug solution) that will be entrapped within the internal compartments of the MLVs.

Technology and Method of Lliposomes Production (PART II)

High-Pressure Extrusion Method
This is another method for converting MLV to SUV suspensions.

Work mechanism of High Pressure Extrusion Method is Suspensions of MLVs prepared by the convectional method are repeatedly passed through filters polycarbonate membranes with very small pore diameter (0.8–1.0µm) under high pressure up to 250psi. By choosing filters with appropriate pore sizes, liposomes of desirable diameters can be produced. As the MLVs are forced through the small pores, successive layers are peeled off until only one remains. Besides reducing the liposome size, the extrusion method produces liposomes of homogeneous size distributions. A variety of different lipids can be used to form stable liposomes by this method. Extrusion at low pressures <1Mpa is possible when lipid concentration is low, but the most commonly used pressures are about 5Mpa.

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