Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 8, pp. 1488−1493.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
T.V. Romanko, Yu.I. Murinov, V.G. Romanko, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 8, pp. 1389−1393.
AND POLYMERIC MATERIALS
Optimization of Rheological Properties of an Adsorption Vaginal
Gel Based on Carbopol
T. V. Romanko
, Yu. I. Murinov
, and V. G. Romanko
Institute of Organic Chemistry, Ufa Scientiﬁ c Center, Russian Academy of Sciences, Ufa, Bashkortostan, Russia
Bashkir State Pedagogical University, Ufa, Bashkortostan, Russia
Received December 11, 2008
Abstract—Rheological properties of adsorption vaginal gels based on Carbopol were examined and compared
with those of Metrogyl (USA). The formulation was optimized by the method of dynamic rheology, and the
rheological extrusion optimum of the vaginal preparation was determined. The activation parameters of the
formulations were calculated.
Aqueous polymeric gels are widely used in production
of cosmetics and pharmaceuticals for improvement of
their rheological characteristics [1–3]. The possibility
of formation of a network structure in microgels is
widely used in various applied programs, in particular,
in production of soft medicinal forms (SMFs).
In the world’s pharmaceutical practice, the most
widely used materials for SMF base are synthetic high-
molecular-weight acrylic acid polymers cross-linked with
sucrose allyl ether or with pentaerythritol. In the leading
pharmacopoeias, these materials are termed carbomers.
The structural formula of carbomers consists of the
following monomeric units :
Carbomers are finely dispersed white powders
consisting of 2–7-μm particles. They can be readily
dispersed in water with the formation of acidic
colloidal solutions having low structural viscosity. After
neutralization, these solutions transform into gels with a
high structural viscosity . Carbomers were chosen as a
base for an adsorption vaginal gel because of the following
advantages: (1) high viscosity at low concentration, (2)
compatibility with many active components, (3) good
bioadhesive properties, (4) temperature stability, and
(5) excellent organoleptic characteristics and good
tolerability by patients [6, 7].
One of the best known carbomer-based soft medinicals
(SMs) for treating bacterial vaginosis is a hydrophilic gel
produced in the United States under the name Metrogyl.
It exhibits an antianaerobic effect. A distinctive feature
of the developed SM is adsorption character of its effect
on the affected area. In bacterial vaginosis (BV), the
affections are local. Hence, the optimal solution is local
treatment, in particular, sorption therapy. Adsorption
vaginal gels are a new generation of SMs.
Because the rheological parameters directly affect
the therapeutic activity of drugs (release, absorbability,
duration of effect, etc.), their optimization and standardiza-
tion is a major technological problem. Problems of
scientiﬁ c substantiation of SMF formulas are covered in
the literature insufﬁ ciently, and therefore they are also
To ensure good therapeutic effect, it is necessary to
provide proper characteristics of drug formulations, so
as to ensure easy application of the gel and its prolonged
contact with the mucous membrane.
In this study we examined the rheological properties
of an adsorption vaginal gel developed on the basis of
a carbomer. The acting substance is Enterosgel (EG)
sorbent. In the development of an adsorption gel, it
was necessary to ﬁ nd the optimal combination of the