Résumé
The objective of this research was to formulate and evaluate hydrodynamically balanced controlled drug delivery system of Losartan. This dosage form is associated with many advantages especially increased bioavailability and reduction in dosing frequency. The formulation was designed adopting optimization technique, which helps in setting up experiments in such a manner that the information is obtained as efficiently and precisely as possible. Initially, considering buoyancy as the main criteria, blank tablets were compressed for different formulae with various polymers like HPMC, MC and EC. The formula selected for design had a combination of Losartan, HPMC, EC and MC. The tablets were prepared by direct compression method and evaluated for Losartan content in vitro release profile and buoyancy. The dissolution study was carried out in simulated gastric fluid using USP dissolution test apparatus employing paddle stirrer. Duration of buoyancy was observed simultaneously when the dissolution has carried out The variation in weight was within the range of ±4% complying with pharmacopoeial specifications (±Z5%). The drug content of Losartan floating tablet 8.455±0.0085 mg in of optimized formulations indicating content uniformity. The buoyancy of the tablets was range 15.345±0.1321 hrs the maximum buoyancy was seen in P6, which has a high level of drug to polymer ratio. The in-vitro release was found to be in the range between the 79.12% to 90.45%.. The formulation P6 has an in vitro release of 79.12% showed the release of the drug in the controlled manner. The optimized formulation P6 exhibited responses that were comparable with that of the predicted values of the design in optimization technique. This indicates the suitability of the technique chosen for the present dosage form.
Résumé
OBJECTIVE: To investigate the effect of polymers, including hydrophilic polymers and swelling aids, on floatability and dissolution of ciprofloxacin hydrochloride gastro-retentive tablets. METHODS: Hydroxypropyl methyl cellulose (HPMC), hydroxyethylcellulose (HEC) and hydroxypropylcellulose (HPC) were used as hydrophilic swelling excipients, and disintegrants crospovidone (PVPP XL and PVPP XL-10) or croscarmellose sodium (CCS) were used as swelling agents to facilitate the swelling/floating and drug release. Initial floating time and floating duration were tested to evaluate buoyance, and drug dissolution was tested to evaluate the controlled release. RESULTS: Using HPMC K250 and PVPP XL as excipients for ciprofloxacin hydrochloride gastro-retentive tablets could obtain products with rapid onset of floating, long floating durion and desirable drug release. CONCLUSION: Variety and amount of polymers have dramatic effects on buoyance and drug release of gastro-retentive tablets. HPMC K250 and PVPP XL are suitable excipients for ciprofloxacin hydrochloride gastro-retentive tablets.
Résumé
The conventional dosage forms stay in the stomach for 0.5-2 hours and passes to small intestine and where it gets absorbed within 3-6 hours. Therefore difficult to adjust release retardation and stomach retention of drug for longer period of time. The present research work was attempted to formulate and evaluate the floating tablet with biphasic release of metoprolol succinate. Metoprolol succinate bioahesive gastric drug delivery system was prepared using bioadhesive polymer PEO, Hydrophylic polymer (Carbopol 71G, HPMC E15, Methacrylic acid, Pectin, Carragenan and Guargum) and gas forming agent Sodium bicarbonate. Metoprolol succinate bioahesive gastric drug delivery system was proved to be attained the effective plasma concentration higher than the Marketed formulation. This is due to retaining metoprolol succinate in the stomach (Where it absorbed more) by means of floating and bioadhesive property of the polymer. Metoprolol succinate bioahesive gastric drug delivery system using PEO and HPMC E15 polymers could be effective sustained release formulation.
Résumé
Freqüentemente recorre-se à produção de sistemas gastrorretentivos para modular a liberação de fármacos a partir de sistemas farmacêuticos com vistas ao aumento do tempo de permanência do fármaco no trato gastrointestinal. Umas das estratégias mais interessantes passa pela produção de sistemas flutuantes. Estes podem ser classificados em dois grupos: sistemas flutuantes efervescentes e sistemas flutuantes não-efervecentes. Neste artigo apresenta-se uma revisão bibliográfica do que tem sido produzido nesta área nos últimos anos.
Gastro-retentive systems are often produced in order to modulate drugs release from pharmaceutical forms and in this way to increase drug residence time in the gastrointestinal tract. One of the most interesting strategies consists in the preparation of floating devices. These can be classified into two groups: effervescent systems and non-effervescent systems. A review of what has been done in the last years is presented in this article.