Prix FOB
Obtenir le dernier prix( Negotiable )
|20 Kilogram Minimum Order
Pays:
China
N ° de modèle:
DS-carbomer-26
Prix FOB:
( Negotiable ) Obtenir le dernier prix
Localité:
Ezhou city,Hubei province,china
Prix de commande minimale:
-
Commande minimale:
20 Kilogram
Packaging Detail:
20kg/paper package
Heure de livraison:
4-10 days
Capacité de Fournir:
1000 Kilogram
Payment Type:
T/T, L/C
Groupe de produits :
Personne àcontacter jing zhao
Business Address:C8-2, Optics Valley United Technology City, Huarong District, Ezhou, Hubei
Factors affecting the properties of carbomer
gel
The carbomer we
produce is a white loose powder with strong hygroscopicity.
Therefore, it must be placed in a plastic bag in a dry place during
storage. When we use carbomer, we usually make a gel and add it to
daily chemicals or medical raw materials. What are the factors that
affect the properties of carbomer gel? Including the pH value and
ionic strength of the medium, the nature of the drug, and the
presence of other excipients.
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Factors
affecting the properties of carbomer gel
1. The
effect of pH
Since the carbomer
polymer has a large number of free carboxyl groups, its pKa value
is usually small. When the pH of the medium is less than 4, the
carboxyl groups hardly dissociate, and when the pH>4, the
carboxyl groups begin to dissociate, the polymer swells, and the
viscosity increases. , When the pH value is 8, the dissociation is
almost complete and the viscosity is the largest. When carbomer is
used as a carrier for basic drugs, after the drug is dissolved, the
pH of the medium increases, the degree of carbomer dissociation
increases, the gel layer thickens, and the drug release rate
decreases, so as to achieve the control of drug release purpose.
The pH value of the medium also affects the adhesion of the
carbomer gel. When the pH value is lower than its pKa, the gel has
a stronger bonding ability and increased adhesion. At the same
time, the ionic strength of the medium can change the sensitivity
of the carbomer gel to pH. When the ionic strength is high, the
carbomer is easier to release protons, and its pKa value decreases,
so it can be dissociated and dissolved at a lower pH.
rise.
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2.
Influence of ionic strength
In some drug
delivery systems, the influence of the drug on the pH and ionic
strength of the medium around the gel is not negligible, because
the pH of the drug will also affect the properties of the gel, and
the effect of acidic drugs is more obvious. The main drug is 2 In
the case of *-dihydroxybenzoic acid, the thickness of the gel layer
is about twice the thickness of the gel layer formed by salicylic
acid as the main drug, which proves that acid drugs will increase
the adhesion of the gel.
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3. The
influence of other excipients
In carbomer gel,
if polyvinylpyrrolidone and polyoxyethylene are used as excipients
at the same time, it may reduce the mucosal adhesion ability of
carbomer gel. This decrease is also related to the concentration
and molecular weight of coexisting excipients, and the
concentration of excipients is high. (5%), can significantly reduce
the adhesion of carbomer gel, when its concentration is reduced to
0.5%, the effect is small. Generally, the pH of the medium cannot
change this property of polyvinylpyrrolidone and polyoxyethylene.
Magnesium stearate can also reduce the adhesion of carbomer gel
because of its hydrophobicity.
| Pays: | China |
| N ° de modèle: | DS-carbomer-26 |
| Prix FOB: | ( Negotiable ) Obtenir le dernier prix |
| Localité: | Ezhou city,Hubei province,china |
| Prix de commande minimale: | - |
| Commande minimale: | 20 Kilogram |
| Packaging Detail: | 20kg/paper package |
| Heure de livraison: | 4-10 days |
| Capacité de Fournir: | 1000 Kilogram |
| Payment Type: | T/T, L/C |
| Groupe de produits : | Carbomer |
