tetracycline and hydroxyethylcellulose

This study describes the formulation, characterisation and preliminary clinical evaluation of mucoadhesive, semi-solid formulations containing hydroxyethylcellulose (HEC, 1-5%, w/w), polyvinylpyrrolidine (PVP, 2 or 3%, w/w), polycarbophil (PC, 1 or 3%, w/w) and tetracycline (5%, w/w, as the hydrochloride). Each formulation was characterised in terms of drug release, hardness, compressibility, adhesiveness (using a texture analyser in texture profile analysis mode), syringeability (using a texture analyser in compression mode) and adhesion to a mucin disc (measured as a detachment force using the texture analyser in tensile mode). The release exponent for the formulations ranged from 0.78+/-0.02 to 1. 27+/-0.07, indicating that drug release was non-diffusion controlled. Increasing the concentrations of each polymeric component significantly increased the time required for 10 and 30% release of the original mass of tetracycline, due to both increased viscosity and, additionally, the unique swelling properties of the formulations. Increasing concentrations of each polymeric component also increased the hardness, compressibility, adhesiveness, syringeability and mucoadhesion of the formulations. The effects on product hardness, compressibility and syringeability may be due to increased product viscosity and, hence, increased resistance to compression. Similarly, the effects of these polymers on adhesiveness/mucoadhesion highlight their mucoadhesive nature and, importantly, the effects of polymer state (particularly PC) on these properties. Thus, in formulations where the neutralisation of PC was maximally suppressed, adhesiveness and mucoadhesion were also maximal. Interestingly, statistical interactions were primarily observed between the effects of HEC and PC on drug release, mechanical and mucoadhesive properties. These were explained by the effects of HEC on the physical state of PC, namely swollen or unswollen. In the preliminary clinical evaluation, a formulation was selected that offered an appropriate balance of the above physical properties and contained 3% HEC, 3% PVP and 1% PC, in addition to tetracycline 5% (as the hydrochloride). The clinical efficacy of this (test) formulation was compared to an identical tetracycline-devoid (control) formulation in nine periodontal pockets (>/=5 mm depth). One week following administration of the test formulation, there was a significant improvement in periodontal health as identified by reduced numbers of sub-

Topics: Acrylic Resins; Algorithms; Anti-Bacterial Agents; Cellulose; Chemistry, Pharmaceutical; Drug Carriers; Excipients; Gels; Humans; Mouth Mucosa; Periodontal Diseases; Povidone; Syringes; Tetracycline; Tissue Adhesives

Tetracycline (TC) as an antibiotic with high consumption causes the spread of contamination in an aqueous solution. In recent decades, antibiotics are the main cause of hindering the growth of microorganisms. Also, they are one of the important groups of pharmaceuticals with extensive usage in human and veterinary medicine. In the first work of its kind, we used a suitable adsorbent of biodegradable hydroxyethylcellulose (HEC) with graphene oxide (GO) by crosslinking ethylene glycol dimethacrylate (EGDMA) and the Fe/Zn with mole ratio 1:1 bimetallic nanoparticles with HEC-GO support. The materials were identified using FTIR, FE-SEM, EDX, TEM, and TG- DSC analyses. The factors affecting the adsorption process (contact time, initial concentration of TC, solution pH, adsorbent dosage, and reaction temperature) were evaluated in a series of batch systems. The adsorption data showed that the high adsorption capacity was obtained on the HEC-GO and HEC-GO/Fe-Zn (mole ratio 1:1) nanocomposites at pH 3. Also, the contact time as the main factor affecting the adsorption process by adsorbents was investigated and the best contact time was 100 and 20 min. The TC removal percentages of both adsorbents were 85% and 95% for HEC-GO and HEC-GO/Fe-Zn, respectively. The maximum adsorption capacity for TC was evaluated by the isotherm models. The experimental data fitted well with the Langmuir model. In addition, pseudo-first-order, pseudo-second-order, intraparticle diffusion, and the Elovich models were applied to kinetic data. The data indicated that TC adsorption on HEC-GO and HEC-GO/Fe-Zn (mole ratio 1:1) followed the pseudo-second-order kinetic model. The thermodynamic parameters implied that the adsorption process was spontaneous and exothermic. Nano-biocomposite (HEC-GO/Fe-Zn) can be used as an adsorbent to remove water pollutants.

Topics: Adsorption; Anti-Bacterial Agents; Graphite; Humans; Hydrogen-Ion Concentration; Kinetics; Nanoparticles; Tetracycline; Water; Water Pollutants, Chemical; Zinc

This study examined the mechanical characteristics and release of tetracycline from bioadhesive, semi-solid systems which were designed for the treatment of periodontal diseases.. Tetracycline release into phosphate buffered saline (pH 6.8, 0.03 M) was examined using a Caleva 7ST dissolution apparatus at 37 degrees C. The mechanical properties of each formulation (hardness, compressibility, adhesiveness, elasticity and cohesiveness) were determined using texture profile analysis. Syringeability was measured using the texture analyser in compression mode as the work of syringeability i.e. the force required to express the product from a periodontal syringe over a defined distance.. Tetracycline release from all formulations was zero-order for 24-54 h and ranged from 1.59 +/- 0.20 to 15.80 +/- 0.50 mg h-1. Increased concentrations of hydroxyethylcellulose (HEC) decreased the rate of release of tetracycline, due to the concomitant increase in product viscosity and the subsequent decreased rate of penetration of dissolution fluid into the formulation. Conversely, an increased polyvinylpyrrolidone (PVP) concentration increased tetracycline release rates, due to an increased formulation porosity following dissolution of this polymer. Increased concentrations of HEC and PVP increased the hardness, compressibility and work of syringeability of the semi-solid formulations, due to increased product viscosity. An increase in formulation adhesiveness, a parameter related to bioadhesion, was observed as the concentrations of HEC and PVP were increased, illustrating the adhesive nature of these polymers. Increased concentrations of HEC and PVP enhanced the semi-solid nature of the product, resulting in decreased product elasticity and cohesiveness. Several statistically significant interactions between polymeric formulation components were observed within the factorial design, with respect to rate of release and all mechanical properties. These interactions arose because of variations in the physical states (dissolved or dispersed) of polymeric formulation components.. The optimal choice of bioadhesive formulation for use in periodontal disease will involve a compromise between achieving the necessary release rate of tetracycline and the mechanical characteristics of the formulation, as these factors will affect clinical efficacy and the ease of product application into the periodontal pocket.

Topics: Acrylic Resins; Adhesives; Anti-Bacterial Agents; Cellulose; Chemical Phenomena; Chemistry, Pharmaceutical; Chemistry, Physical; Drug Administration Routes; Humans; Periodontal Diseases; Periodontal Pocket; Pharmaceutic Aids; Polymers; Povidone; Tetracycline