Xanthan gum

The present study was aimed to develop and optimize extended release (ER) matrix tablets of Lamivudine trilayer tablets to achieve zero-order drug release for prolonged period of time. Lamivudine tablets were prepared by direct compression and consist of middle active layer with different grades of HPMC, MCC and PVP K30, upper and lower layers were prepared with Carnauba wax, Xanthan gum, EC and MCC. The tablets were also evaluated for physicochemical characteristics and release kinetics. The physicochemical characteristics of the prepared tablets were satisfactory. The developed drug delivery systems showed prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (HF23) was described by the Zero-order and Higuchi model. The results indicate that the approach used could lead to a successful development of extended release formulation of short biological half-life drug. These results also demonstrated the suitability of three-layered tablet formulation of Lamivudine to provide controlled release for prolonged period of time and improved linearity for Lamivudine in comparison to marketed product in the effective management of AIDS with patient compliance.

The purpose of present work was for formulation and characterization of Clopidrogrel floating tablets to improve bioavailability and to minimize the side effects of the drug. FTIR studies were conducted for drug polymer compatibility. The Clopidrogrel sustained release floating tablets were formulated by wet granulation method.  Tablets were subjected to pre and post compressional evaluation studies. The different concentrations of HPMC K4M, HPMC K15M, xanthan gum, guargum, and sodium bi carbonate 25% w/w is used as gas generating agent and micro cellulose crystalline MCC are used in different concentrations (75%, 50%, 25%) as diluent. The tablets were tested for thickness, weight variation, hardness, friability, drug content; In vitro floating parameters and drug release studies were also conducted. Compatibility studies revealed that there is no interaction between drug and polymers in the formulations. The flow properties were within the limits and the granular bed exhibited uniform flow and ease for compression. Clopidogrel floating tablets showed uniform post compressional properties with minimum standard deviation. The formulations showed minimum floating lag time and prolonged duration of floating. In vitro drug release of clopidogrel was sustained up to 12 h. Clopidrogrel release followed zero order, first order, Higuchi drug release kinetics for drug release. The peppas diffusion coefficient ranged from 0.455 - 0.895 indicating drug release by non fickian diffusion followed by erosion. The F4 floating tablet was optimized formulation which showed 100% release sustained for 12 h. The stability studies indicated stability of drug in the optimized formulation against temperature and humidity.

The objective of present study was to prepare and evaluate Zaltoprofen (ZLT) enteric coated oral mucoadhesive sustained release (SR) tablet in order to improve its GI residence time and improve its bioavailability by using natural biopolymers like xanthan gum and semisynthetic polymer HPMC for its safe use in rheumatoid arthritis, osteoarthritis, ankylosing spondylitis condition. The sustained release polymers, hydroxypropyl methylcellulose (HPMC) of different viscosities and xanthan gum evaluated in different proportions as a major matrix material. Drug-polymer compatibility studies by FTIR and DSC gave confirmation about their purity and showed no interaction physically between drug and selected polymers. ZLT matrix tablets were prepared by wet granulation.  The effect of polymer concentration on the drug release profile and in-vitro bioadhesion of the matrix tablets was studied. A 32 full factorial design was utilized in the optimizing the levels of HPMC and Xanthan gum. Concentration of HPMC K4M and the concentration of xanthan gum per tablet were used as the independent variables.  The dependent variables were the bioadhesive strength, percent drug dissolved at 2, 6 and 10 hours. The data obtained were fit to a model and polynomial equations were generated. Response surface graph was generated based on these equations. Formulation composition with desired release characteristics and bioadhesive strength were found to be predictive using this model. The optimized factorial batch was further given the coating of Opadry® enteric (94 series) polymer in order to avoid GI disturbances. The Z-22 tablets were kept for stability study at 40°C ±2°C and 75% ± 5% RH for a period of 6 months according to ICH guidelines. The formulation was found to be stable after 6 months of study. The pharmacokinetic parameters Cmax, Tmax, Mean Residence Time (MRT) and Area under Curve (AUC) of developed SR tablet were found to be improved with significant difference (p

The objective of this research work was to formulate and evaluate the floating drug delivery system containing Pantoprazole sodium sesquihydrate as a model drug and to optimize its drug release profile. Pantoprazole sodium tablets were prepared by direct compression technique. Formulations contained Xanthan gum, PVP K30 and gas generating agent such as sodium bicarbonate and citric acid were taken as independent variables. The physical parameters of the tablets were characterized and were found within the limits. By comparing dissolution profiles of different formulations, the formulation F5 was considered as a better formulation. The drug release from all the formulations was found to follow zero order kinetics and Peppas modeling. The diffusion exponent of formulations was found (n

The present research paper focuses on designing not only the sustained release tablets of acyclovir to ensure time-dependent, sustained release formulation but also studying the effect of sodium alginate, Xanthan gum and HPMCV K15 on the in vitro release profile of the tablet. The initial release of drug from these matrices occurs by the drug dissolution in the water penetrated into the matrix. The overall drug release from these matrices is governed by hydration, gel layer formation and drug diffusion into the gel layer and to the dissolution media. The formulations ACL1 to ACL5 are containing 200mg of drug with a combination of different excepients. The drug release showed in ACL1 was 95.78%, for only 10hrs and ACL2 showed 90.66% within 11hrs because there was less presence of Xanthan Gum. The Acyclovir tablets of ACL3 showed 91.35% in 12hrs, ACL4 and ACL5 showed drug release of 95.33% for 8hrs and 95.85% for 9hrs. In further formulations the dose of Acyclovir was increased to 400mg ACL6 to ACL10 that are containing combination of excipients. The drug release for the formulations ACL6 showed a drug release of 97.44% for 10hrs and ACL7 showed a drug release 92.4% for 11hrs. From these twelve formulations it was concluded that increase in concentration of Xanthan Gum and Sodium alginate overrun the effect of HPMC K15. The dissolution characteristics allowed for drug to be released in a controlled manner, highlighting the importance for the correct selection of polymers according to their physical, mechanical and pharmacokinetic properties.

The aim and objective of the study was to formulate the matrix system of Loxoprofen sodium that has a very short plasma half-life of 1.15 hours. Natural hydrophilic polymers (Xanthan gum and Pectin) were used to formulate matrix system. These polymers were used to sustain the drug in the matrix system that allowed the slow release of the drug. Different concentration of Xanthan gum and Pectin were used, individually as well as polymeric blends. Wet granulation method was selected for the compression of granules into tablets of 350mg each. Both pre-compressional and post-compressional parameters showed good results. Dissolution studies carried out in distilled water and 0.1 N HCl for 12 hours.  Matrix system of Xanthan gum showed comparatively good sustained effects in both media with suitable drug released concentration. Kinetics of drug release was studies by different kinetics models and it was observed that Higuchi was the best fit model for F6 that released minimum drug from the matrix. Values of similarity index showed that F5 resembled with the reference formulation (F6). All the tablets showed good swellability upon hydration that was greatly related to polymers concentration.

The present study was carried out in fabricating gastro retentive formulation of an antipsychotic drug using semi synthetic and natural polymers. Floating tablets were prepared by direct compression method using directly compressible microcrystalline cellulose as vehicle. Gum Xanthan and hydroxypropyl methylcellulose (HPMC E4M) were used as polymers for sustaining the drug release and sodium bicarbonate was used as an effervescent agent. Tablets were characterized for their pre compression and post compression parameters. Floating characteristics like floating lag time, floating time were evaluated and were considered as one of the factor for selecting the best formulation. The in vitro release studies were carried out in pH 1.2 buffer for 8hrs. The content uniformity was found to be within the compendial requirements and the release was extended for more than 8hrs. The best fit release kinetics was achieved with zero order followed by higuchi and non-fickian diffusion. The release of Quetiapine fumarate was significantly influenced by the concentration of polymer.

As a site for drug delivery the oral cavity offers advantages over the conventional gastrointestinal route and the parenteral and other alternative routes of drug administration. It provides direct entry into the systemic circulation thereby avoiding the hepatic first pass effect. Verapamil HCl belongs to a drug group of calcium channel antagonists. The oral absorption of the drug from these forms is 90% but its bioavailability approaches only 10–20%, due to a extensive first-pass effect. Here attempt is made to extract mucilage and use as gelling and mucoadhesive agent. The yield of natural mucoadhesive fenugreek extract was 28-29 percent. Fenugreek mucilage shows synergistic effect with xanthan gum and provide higher viscosity. Fenugreek is used with xanthan gum in the selected ratio of 2.5:1. Different parameters were evaluated like % yield of fenugreek, viscosity, gel strength, mucoadhesive study, in-vitro diffusion study, ex-vivo permeation study and differential scanning calorimetry. The mucosal permeation of drug from the formulation was evaluated using Franz diffusion cell, goat buccal mucosa as semi-permeable membrane. The amount of the drug released was determined by evaluating drug diffused through the membrane by using UV- spectrophotometry. The verapamil HCl release was sustained up to 6 hrs by optimizing concentration of fenugreek and xanthan gum.

Different formulation technologies intended for gastro retentive dosage form were investigated and patented over the years. The aim of this study was to formulate, optimize and evaluate the gastro retentive floating tablet of stavudine. The developed technology induces a low density dosage form containing high concentration of active pharmaceutical ingredient (API). In the present work, the in-vitro sustained release of stavudine from matrix of tablet containing HPMC K100M and Xanthan gum as release retardant polymers has been studied. Sodium bi-carbonate and citric acid are used as gas generating agents. The tablets were prepared by direct compression method. The tablets eroded upon contact with the release medium 0.1N HCl and  the relative importance of floating lag time,% swelling index and % drug release patterns varied significantly with the concentration of polymers. Optimization was done by using design expert 8.0.4.1 and optimized formulation F6 of stavudine floating tablet shows no significant change in hardness, drug content, floating lag time and % cumulative drug release pattern after the stability period of 3 months at 400c/75% relative humidity. Key-words- Stavudine, HPMC, Xanthan gum, floating tablet, in vitro buoyancy.