Floating Drug Delivery System: A New Approach

Floating drug delivery system (FDDS) helps to improve the buoyancy property of the drug over the gastric fluids and hence maintain the longer duration of action. The aim of the present study is on floating drug delivery systems (FDDS) was to compile the recent literature with particular focus on the main floating mechanism to achieve gastric retention. Floating multi-particulate are gastro-retentive drug delivery systems which are based on non-effervescent and effervescent approach. This type of drug delivery method would have comparatively less side effect and would eliminate the need for repeated dosages.

Development of a new single unit dosage form of propranolol HCl extended release non-effervescent floating matrix tablets: In vitro and in vivo evaluation.

The objective of the present investigation was to develop extended release non-effervescent floating matrix tablets of Propranolol Hydrochloride (PPH) to extend the gastric residence time (GRT) and prolong the drug release after oral administration. Different viscosity grades of Hydroxypropyl methylcellulose (HPMC) polymers such as HPMC K4M, HPMC K15M and HPMC K100M were used as drug release retardants. Glyceryl behinate (Compritol 888 ATO) and Glyceryl monosterate (Precirol ATO 5) were used as low density lipids in order to get the desired buoyancy over a prolonged period of time. The drug excipients compatibility study was carried out by using Differential Scanning Calorimetry (DSC). All the formulations were prepared by direct compression technique. The prepared tablets were evaluated for their physical characters, in vitro drug release and in vitro buoyancy. The release and floating property depends on the polymer type, polymer proportion, lipid type and lipid proportions. The drug release profiles of all the formulations were subjected to Zero order, First order, Higuchi and Peppas kinetic models, and the optimized formulation (F7) followed the Peppas model (R2= 0.987) with non-Fickian diffusion mechanism(n>0.5). The optimized formulation was subjected for in vivo radiographic studies in healthy human volunteers (n=3). These studies revealed a mean gastric residence time of 5±1.73 h (n=3).

Formulation and in Vitro Evaluation of Ketoprofen Gastric Floating Matrix Tablet Based on Gas Formation.

The purpose of this study was to develop a gastroretentive drug delivery system of ketoprofen with suitable swelling and floating properties to reduce its irritant effect on the stomach and prolong its short duration of action up to 12 h. Floating tablets were prepared employing EC (ethylcellulose), NaCMC (sodium carboxy methylcellulose), HPMC K4M (hydroxypropyl methylcellulose) (release retarding polymers), Sodium bicarbonate (gas-generating agent), Lactose and Avicel (fillers) by gas formation technique. Tablets were evaluated for drug content, weight variation, hardness, thickness, floating behavior, swelling ability and invitro drug release in 0.1 N HCl containing tween 20. The optimized formulations of F3, F4 and E2 exhibited prolonged drug release for 12 h, with short lag time (≤3 min) and long floating duration (≥24 h). ANOVA post hoc multiple comparisons was conducted for significance at P<0.05. Based on kinetic studies, formulations best fitted to Higuchi model. The results indicated that type and amount of polymer, type of fillers and amount of gas generating agent have influenced on drug release and floating behavior.

Microballoons: A better approach for gastro retention.

The purpose of this review is to accumulate the recent study on floating drug delivery system with special emphasis on microballoons as drug delivery. Microballoons are emerging as the most promising drug delivery as it overcome many limitations of conventional drug delivery system. As microballoons delivery system provides longer retention in gastric pH, hence longer is the residence time and therefore enhance the solubility of drugs that are less soluble in high pH environment. The formation of cavity inside the microsphere depends upon the preparation temperature and the surface smoothness determines the floatability and the drug release rate of the microballoons. The review includes the classification, advantages, disadvantages, method of preparation and future aspects of microballoons. Basic anatomy and physiology of stomach is also studied.

Formulation and evaluation of novel stomach specific floating microspheres bearing famotidine for treatment of gastric ulcer and their radiographic study

Objective: To develop and characterize multiple-unit-type oral floating microsphere of famotidine to prolong gastric residence time and to target stomach ulcer. Methods: The floating microspheres were prepared by modified solvent evaporation method. Eudragit S-100 was used as polymer. Microspheres were characterized for the micromeritic properties, floating behavior, entrapment efficiency and scanning electron microscopy. The in-vitro release studies and floating behavior were studied in simulated gastric fluid at pH 1.2. Different drug release kinetics models were also applied for all the batches. Selected formulations were also subjected for X-ray radiographic study. Results: Floating microspheres were successfully prepared by modified solvent evaporation technique. Microspheres showed passable flow properties. The maximum yield of microspheres was up to (95.11±0.35)%. On the basis of optical microscopy particle size range was found to be ranging from (52.18±182.00) to (91.64±5.16) μm. Scanning electron microscopy showed their spherical size, perforated smooth surface and a cavity inside microspheres. Microspheres were capable to float up to 20 h in simulated gastric fluid. X-ray radiographic studies also proved its better retention in the stomach. Conclusions:On the basis of the results, such dosage forms may be a good candidate for stomach targeting and may be dispensed in hard gelatin capsules.

Formulation of gastroretentive floating drug delivery system using hydrophilic polymers and its in vitro characterization

The aim of the present research is to formulate and evaluate the gastroretentive floating drug delivery system of antihypertensive drug, propranolol HCl. Gastroretentive floating tablets (GRFT) were prepared by using a synthetic hydrophilic polymer polyethylene oxide of different grades such as PEO WSR N-12 K and PEO 18 NF as release retarding polymers and calcium carbonate as gas generating agent. The GRFT were compressed by direct compression strategy and the tablets were evaluated for physico-chemical properties, in vitro buoyancy, swelling studies, in vitro dissolution studies and release mechanism studies. From the dissolution and buoyancy studies, F 9 was selected as an optimized formulation. The optimized formulation followed zero order rate kinetics with non-Fickian diffusion mechanism. The optimized formulation was characterised with FTIR studies and observed no interaction between the drug and the polymers.

O objetivo da presente pesquisa é o de formular e avaliar o sistema de liberação de fármaco gastrorretentivo flutuante, contendo o anti-hipertensivo, cloridrato de propranolol. Comprimidos gastrorretentivo flutuantes (GRFT) foram preparados utilizando um polímero hidrofílico sintético, o óxido de polietileno, de diferentes graus, tais como GE WSR N-12 K e GE 18 NF, como polímeros de retardamento de liberação, e carbonato de cálcio, como agente gerador de gases. Os GRFT foram comprimidos por compressão direta e avaliados para determinação das propriedades físico-químicas, flutuabilidade in vitro, estudos de inchamento, de dissolução in vitro e de mecanismo de liberação. Dos testes de dissolução e de flutuabilidade, selecionou-se F 9 como formulação otimizada. A formulação otimizada seguiu cinética de ordem zero, com mecanismo de difusão não-Fickiano. Essa formulação foi caracterizada por estudos de FTIR, não se observando interação entre o fármaco e os polímeros.

Formulation and evaluation of novel stomach specific floating microspheres bearing famotidine for treatment of gastric ulcer and their radiographic study

Objective: To develop and characterize multiple-unit-type oral floating microsphere of famotidine to prolong gastric residence time and to target stomach ulcer. Methods: The floating microspheres were prepared by modified solvent evaporation method. Eudragit S-100 was used as polymer. Microspheres were characterized for the micromeritic properties, floating behavior, entrapment efficiency and scanning electron microscopy. The in-vitro release studies and floating behavior were studied in simulated gastric fluid at pH 1.2. Different drug release kinetics models were also applied for all the batches. Selected formulations were also subjected for X-ray radiographic study. Results: Floating microspheres were successfully prepared by modified solvent evaporation technique. Microspheres showed passable flow properties. The maximum yield of microspheres was up to (95.11±0.35)%. On the basis of optical microscopy particle size range was found to be ranging from (52.18±182.00) to (91.64±5.16) μm. Scanning electron microscopy showed their spherical size, perforated smooth surface and a cavity inside microspheres. Microspheres were capable to float up to 20 h in simulated gastric fluid. X-ray radiographic studies also proved its better retention in the stomach. Conclusions: On the basis of the results, such dosage forms may be a good candidate for stomach targeting and may be dispensed in hard gelatin capsules.

Influence of Sodium CMC and HPMC on the Physical Characteristics of Ofloxacin Floating Matrix Tablets.

Aims: Sustained release floating drug delivery systems or gastro retentive drug delivery systems enables prolonged and continuous input of drug to the upper part of gastrointestinal tract and improves the bioavailability of medication. A new strategy is proposed for the development of floating drug delivery systems of Fluoroquinolone antibiotic, Ofloxacin, a potent moiety for treating UTI’s. Methodology: Various rate retarding polymers like HPMC K4M, HPMC 5 cps and swelling agent as Sodium carboxymethyl cellulose in different proportions were tried and optimized to achieve the drug release for 8 hr. All the formulations were evaluated for floating properties, swelling characteristics and in vitro drug release studies. The in vitro drug release was found to be matrix diffusion controlled. Optimized formulation was subjected to intermediate stability studies at various combinations of temperature and humidity according to ICH guidelines. Results: Lower hardness and higher thickness decreased the floating lag time and increased floating duration. Based on drug release studies, formulation F5 was optimized as the best formulation because it released about 89.27 ±2.6% of the drug at the end of 8 hr while other formulations released not more than 80 ±2.2%. This may be due to high NaCMC content which might have caused excessive channeling, thereby giving a burst release. Optimized formulation F5 was found to follow zero order kinetics with r2 value of 0.993. Conclusion: In conclusion we have been proved that HPMC K4M has retarded the drug release, while HPMC 5cps has facilitated high buoyancy time for the tablets. NaCMC has influenced as channeling agent. Formulation F5 was optimized for its long buoyancy time, prolonged duration of drug release, zero order and diffusion controlled drug release kinetics which can assure 100% bioavailability.

Floating drug delivery system.

The aim of writing this review on gastro retentive and floating drug delivery system was to compile the new literature with the principle mechanism of floatation to acquired gastric retention. Various attempts have been made to develop gastroretentive delivery systems such as high density system, swelling, floating system. In floating multiple unit and single unit system are design and their classification and formulation aspect is cover in detail. These systems are very helpful to different problem solve during the formulation of different dosage form. In this review the gastric physiology and reported intra gastric delivery system have briefly been presented.