Effect of Thiolated Polymers to Textural and Mucoadhesive Properties of Vaginal Gel Formulations Prepared with Polycarbophil and Chitosan

Abstract

The aim of this study was to design and evaluate of mucoadhesive gel formulations for the vaginal application of clomiphene citrate (CLM) for local treatment of human papilloma virus (HPV) infections. Chitosan (CHI) and polycarbophil (PC) were covalently modified using the thioglycolic acid and L-cysteine, respectively. The formation of thiol conjugates of chitosan (CHI-TG) and polycarbophil (PC-CYS) were confirmed by FT-IR analysis and PC-CYS and CHI-TG were found to have 148.42 +/- 4.16 and 41.17 +/- 2.34 micromol of thiol groups per gram of polymer, respectively. One percent CLM gels were prepared by combination of various concentrations of PC and CHI with thiolated conjugates of these polymers. Hardness, compressibility, elasticity, adhesiveness and cohesiveness of the gels were measured by Texture profile analysis and the vaginal mucoadhesion was investigated by mucoadhesion test. The increasing in the amount of the thiol conjugates was found to enhance the elasticity, cohesiveness, adhesiveness and mucoadhesion of the gel formulations but not their hardness and compressibility when compared to gels prepared using their respective parent formulations. Slower release rate of CLM from gels was achieved when the polymer concentrations were increased in the gel formulations. PC and its thiol conjugate were found to prolong the release of CLM longer than 70 h unlike gel formulations prepared using CHI and its thiol conjugate which were able to release CLM up to 12 h. Stability of CLM was preserved during the 3 month stability analysis under controlled room temperature and accelerated conditions.

Design and Evaluation of Polysaccharide-Based Transdermal Films for the Controlled Delivery of Nifedipine

“…From the resultant forcetime plot, mechanical parameters such as hardness, compressibility, cohesiveness and elasticity of the gel formulations were defined. [28][29][30] Preparation of Transdermal Films Transdermal film formulations containing different concentrations of NFD (1.0-10.0% w/w) were fabricated using the polymers (pectin and sodium alginate) and plasticizers (glycerine and propylene glycol) which were selected as a result of the preliminary formulation studies (Table 1).…”

Optimization of Biopolymer Based Transdermal Films of Metoclopramide as an Alternative Delivery Approach

“…Our results are given in Table 2 and Figure 3. The hardness parameter represents the strength of the gel structure under compression and introduces the required force to provide the deformation of a gel formulation [30]. In the present study it is found that the hardness values of MTC gels were between 0.02 ± 0.01 and 0.01 ± 0.02.…”

“…A low hardness value has been reported as an advantage for administration to the skin or mucosa easily [35]. The hardness influences the pourability and spreadability of the gel into film molds [30]. The gel formulations G-NR, G-EU, G-TP, and G-LM in our study flowed properly and spread homogenously when poured into the film molds indicating that the obtained hardness values were appropriate.…”

“…It significantly affects the elasticity and homogeneity of the films to be prepared by using these gels. The increase in the quantitative value of elasticity showed the decrease in the elasticity of the gel formulation [30,36]. We observed that eucalyptol containing gel formulation G-EU showed the highest elasticity value (0.87 ± 0.05).…”

“…The resultant force-time plots were used for determination of the mechanical properties. Data evaluation was performed using the Texture Exponent software package of the instrument [5,30,31].…”