Design, development and in vitro-in vivo study of colon specific fast disintegrating tablet based on time dependent approach

Targeted delivery systems for treatment of Inflammatory bowel disease (IBD) are designed to increase local tissue concentrations of anti-inflammatory drugs from lower doses compared with systemic administration The objective of this study was to formulate and evaluate an oral system designed to achieve site specific and instant drug release in colon for effective treatment of IBD based on time dependent approach. The system consists of core tablet containing model drug diclofenac sodium, superdisintegrant sodium starch glycolate, and coated with pH independent polymer Eudragit RSPO to achieve different total percentage weight gain. Drug release studies were carried out using changing pH method. Placebo formulation containing barium sulphate in the tablet was administered to human volunteers for in vivo X-ray studies. In vitro studies revealed that tablet with 5 % coating level release the drug after 5 h lag time corresponding to the colonic region. Tablets with 5 % coating level could maintain their integrity in human volunteers for 5 h, approximating colon arrival time and release the drug instantaneously. Colon targeting and instant drug release for 5 % coating level was due to swellable hydrophilic polymer, which is responsible for a lag phase preceding the onset of release and the immediate release effect of superdisintegrant, It was observed that as coating level increases, lag time also increases. This is because of increased diffusion path length and tortuosity at higher coating levels. In vivo - in vitro study reveals thickness of coating of Eudragit RSPO play an important role in colon delivery and tablet with superdisintegrant and 5 % coating level achieved the desired performance of the colon targeting.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Evaluation of oral fast disintegrating tablet of taste masked famotidine in rat

The purpose of this research was to formulate fast-disintegrating tablets of famotidine by using tasteless complex of famotidine. Famotidine is a commonly used antiulcer drug but major disadvantage is its bitterness and low bioavailability. A fast-disintegrating dosage form has been developed as a user- friendly formulation that disintegrates in the mouth immediately. In this study the bitter taste of famotidine was masked by making complex with ion exchange resin Indion 214. The drug-resin complexes were characterized by infrared spectroscopy and thermal analysis. Famotidine oral fast disintegrating tablets were prepared by direct compression method by using different superdisintegrants. The prepared tablets were found to comply with various official specifications. Tablet containing crospovidone as superdisintegrating agent showed superior organoleptic properties, along with excellent in vitro disintegrating time and drug release, as compared to other formulation. The in vivo anti ulcer activity in rats shown that there was no bioavailability change due to complexation and tablet had good antiulcer activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhesion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 32 factorial design was employed in formulating and optimizing the GRDDS for bilayer tablet of CP and HCTZ matrix tablet. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The gastroretentive ability of the tablets was evaluated by X-radiographic studies in healthy human volunteer. The tablet releases CP and HCTZ for extended period up to 24 h in controlled manner. The predicted values agreed well with the experimental values and the results demonstrate the feasibility of the optimization methodology in the development of GRDDS. The tablet was buoyant for up to 16 h in human stomach. Development of once a day gastroretentive formulation of CP and HCTZ improves the patience compliance and bioavailability of drugs.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Formulation and in-vitro evaluation of repaglinide microspheres prepared by spray drying technique

Repaglinide is a potent second generation oral hypoglycaemic agent widely used in treatment of non insulin dependent diabetic mellitus. The objective of the present study was to develop sustained release microspheres of repaglinide using ethyl cellulose and PEG 6000 as a matrix forming polymer. Microspheres were prepared by taking various concentrations of ethyl cellulose and PEG 6000 by spray drying technique. Prepared microspheres were evaluated for process yield, drug entrapment, particle size, SEM, FTIR, DSC and in vitro drug release. Process yield and drug entrapment was 40-45 % and 90-95 %, respectively. Particle size ranged in 5-22 µm and SEM study showed spherical shape and rough surface of microspheres. FTIR study and DSC analysis revealed the stable nature and amorphous dispersion of drug in the polymer matrix. In vitro release studies indicate retardation of release upto 12 h which can control both fasting blood glucose level and postprandial blood glucose.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Taste masking of cefuroxime axetil by ion exchange resin complex

The antibiotic cefuroxime axetil is extremely bitter. The present study deals with development of taste-masked resinates of cefuroxime axetil using ion exchange resins. The drug resin complexation procedure was optimized with respect to drug to resin ratio and pH of medium. Taste masked complex was characterized by FTIR, DSC and XRPD studies. In vitro release studies revealed complete drug release from the complex within 120 min in 0.1N HCl solution whereas less than 5 % drug was released from taste masked complex in 60 sec in simulated salivary fluid (pH 6.2) which found to be insufficient to impart bitter taste. The taste-masked complex was then formulated into a suspension dosage form using sodium carboxymethyl cellulose as suspending agent. The suspension was evaluated for various quality control parameters and in vivo studies were carried out to check bioavailability of drug from suspension.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhesion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 32 factorial design was employed in formulating and optimizing the GRDDS for bilayer tablet of CP and HCTZ matrix tablet. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The gastroretentive ability of the tablets was evaluated by X-radiographic studies in healthy human volunteer. The tablet releases CP and HCTZ for extended period up to 24 h in controlled manner. The predicted values agreed well with the experimental values and the results demonstrate the feasibility of the optimization methodology in the development of GRDDS. The tablet was buoyant for up to 16 h in human stomach. Development of once a day gastroretentive formulation of CP and HCTZ improves the patience compliance and bioavailability of drugs.Colegio de Farmacéuticos de la Provincia de Buenos Aire