Development and Evaluations of Aceclofenac Microcapsules for Colon-Targeted Delivery: An In Vitro Study (original) (raw)
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Dual coated erodible microcapsules for modified release of diclofenac sodium
European Journal of Pharmaceutics and Biopharmaceutics, 2004
Diclofenac sodium was formulated as novel enteric microcapsules for improved delivery to the intestine using the polymers cellulose acetate phthalate (CAP) and ethyl cellulose (EC). The enteric coating was given using an innovative technique combining the wet granulation and thermal change methods. The novel process was analysed for its capability to produce microcapsules of uniform size, good flowability, uniform drug loading and maximum entrapment efficacy and the absence of interaction between drug and process parameters as well as the polymers. In vitro release study was carried out in simulated gastric fluid (SGF) for first 2 h and simulated intestinal fluid (SIF) for next 6 h. The best formulation that contained cellulose acetate phthalate and ethyl cellulose in the concentration of 10:90 at 1:1.5 drug-polymer ratio (B3) was further evaluated using in vivo for its pharmacodynamic efficacy and ulcerogenicity. In addition to sustained and uniform release of drug, the formulation B3 showed better anti-inflammatory activity than the marketed formulation and retarded drug release in the gastric medium. The biological examination of incised stomach showed no histological alterations in term of mucous surface cells and glands.
Prolonged-release microcapsules of diclofenac sodium (DS) were prepared by employing ethyl cellulose as a polymer in various ratios of 1:1, 2:3 & 2:1, by emulsion solvent evaporation technique. Scanning electron microscope photographs of samples revealed that all prepared microcapsules were almost spherical in shape and have a slightly smooth surface. The encapsulation efficiency was found to be in the range of 66.17-72.99%. The in vitro release profile of diclofenac indicates that all the batches of microcapsules showed controlled and prolonged drug release over an extended period of 10 h. The release kinetics study reveals that the drug follows first order kinetics and the mechanism of drug release was diffusion controlled type. From the in vitro drug release profiles, it was also observed that the drug release from microcapsules was decreased with an increase in coating material in the microcapsules. Infrared spectroscopic studies indicate that there is no chemical interaction between drug and carrier, and the drug is stable in the formulated microcapsule product.
Controlled drug delivery through microencapsulation
2006
An appropriately designed controlled release drug delivery system can be a major advance towards solving problems concerning to the targeting of drug to a specific organ or tissue and controlling the rate of drug delivery to the target site. The development of oral controlled release systems has been a challenge to formulation scientist due to their inability to restrain and localize the system at targeted areas of gastrointestinal tract. Microparticulate drug delivery systems are an interesting and promising option when developing an oral controlled release system. The objective of this paper is to take a closer look at microparticles as drug delivery devices for increasing efficiency of drug delivery, improving the release profile and drug targeting. In order to appreciate the application possibilities of microcapsules in drug delivery, some fundamental aspects are briefly reviewed.
Heliyon
The current study was to improve and control aceclofenac delivery prepared as biopolymer-based microparticles for effective colon-targeted drug delivery using modified gelatin capsules (MGCs) at different time intervals developed in two batches (C1 and C2). Microparticles were formulated with extracted mucuna gum using liquid paraffin oil (AC.LPO) and soybean oil (AC.SO) and evaluated in vitro for physicochemical performance and in vivo in rats. Encapsulation efficiency ranges from 54.48 AE 0.21% to 82.83 AE 0.22% for AC.LPO and 52.64 AE 0.11% to 80.36 AE 0.22% for AC.SO. SEM showed oblong and irregular shapes with porous and cracked surfaces. DSC showed low enthalpy and a very broad endothermic peak depicting high amorphous property. Delayed drug release was observed in the upper gastrointestinal tract with sustained release depicted in the lower gastrointestinal tract (GIT) using 3 and 9-h batch C1 of MGCs. AC.SO exhibited significantly (p < 0.05) higher antiinflammatory activity (86%) than AC.LPO (77%). Hence, aceclofenac colon delivery could be improved and controlled using biopolymer-based colon-targeted microparticles delivered with MGCs.
2011
This article demonstrated development of controlled release system of an NSAID drug, Diclofenac sodium employing different ratios of Ethyl cellulose. Diclofenac sodium and ethyl cellulose in different proportions were processed by microencapsulation based on phase separation technique to formulate microcapsules. The prepared microcapsules were then compressed into tablets to obtain controlled release oral formulations. In-vitro evaluation was performed by dissolution test of each preparation was conducted in 900 ml of phosphate buffer solution of pH 7.2 maintained at 37 ± 0.5 °C and stirred at 50 rpm. At predetermined time intervals (0, 0.5, 1.0, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 20 and 24 hrs). The drug concentration in the collected samples was determined by UV spectrophotometer at 276 nm. The physical characteristics of diclofenac sodium microcapsules were according to accepted range. These were off-white, free flowing and spherical in shape. The release profile of diclofenac sodiu...
Preparation and characterization of aceclofenac microspheres
Asian Journal of Pharmaceutics, 2008
T he objective of the present study was to microencapsulate the anti-inflammatory drug (aceclofenac) to provide controlled release and minimizing or eliminating local side effect by avoiding the drug release in the upper gastrointestinal track. The drug was targeted to the colon and their aligned area for their local effect. Aceclofenac was microencapsulated with Eudragit (S 100, RL 100, and RS 100), using an O/W emulsion-solvent evaporation technique. Aceclofenac microspheres were subjected to micromeritic properties including angle of repose, bulk density, tapped density, Carr's index, Hausner's ratio, and particle size determination. Microspheres were subjected to drug loading, in vitro drug release as well as for scanning electron microscopy. The prepared microspheres were white, free-flowing, and almost spherical in shape. The drugloaded microspheres show 60-82% drug entrapment, angle of repose was in the range of 16.13 ± 0.621-24 ± 0.590, bulk and tapped densities respectively were in the range of 0.311 ± 0.006-0.562 ± 0.012 and 0.373 ± 0.01-0.735 ± 0.02, Carr's index ranges from 14.04 ± 0.026 to 27.25 ± 1.405, Hausner's ratio was 1.14 ± 0.026-1.37 ± 0.03, and particle size was in the range of 79.7016-144.840 µm. In vitro drug release studies were carried out up to 24 h in three different pH media, i.e., 0.1 N HCl (pH 1.2), phosphate buffer (pH 6.8), and phosphate buffer (pH 7.4). The drug-polymer concentration of dispersed phase influences the particle size and drug release properties. All the formulations at higher pH were followed by the Matrix-Higuchi model.
2014
The purpose of the present work was to develop optimized novel enteric microcapsules containing diclofenac sodium, a non steroidal anti inflammatory drug (NSAID) used for rheumatoid arthritis, for improved delivery and to diminish its adverse effect after oral administration. The microcapsule was prepared by using different polymers and the enteric coating was provided by using an innovative technique combining wet granulation method and thermal change method. This work also investigated different levels of enteric polymers like cellulose acetate phthalate (CAP) (X1) and ethyl cellulose (EC) (X2) and the stirring speed during coating ethyl cellulose (X3), by using 23 full factorial design. The dependent variables assessed were % yield (Y1), Q8 (% drug released after 8 hour) (Y2), n (Diffusion coefficient) (Y3), DEE (Drug entrapment efficiency) (Y4). The main effect and interaction terms were quantitatively evaluated using a mathematical model. The prepared microcapsules were evaluat...
Pharmacology & Pharmacy, 2011
Polymethylmethacrylate (PMMA) coated microcapsules of diclofenac sodium (DFS) were prepared by a modified water-in-oil-in-water (W 1 /O/W 2 ) emulsion solvent evaporation method using sodium alginate (SAL) as a matrix material in the internal aqueous phase (W 1 ). Their performance with respect to controlled release of the drug in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were evaluated, and compared with non-matrix microcapsules prepared by the conventional W 1 /O/W 2 emulsion solvent evaporation method. Scanning electron micrographs (SEM) revealed that all the microcapsules were discrete and spherical in shape; however, the surface porosity of the matrix microcapsules appeared to be less than that of the non-matrix microcapsules. In case of non-matrix microcapsules, an increase in the volume of water in W 1 phase resulted in decrease in the drug entrapment efficiency (DEE) along with increase in release of the drug in both SGF and SIF. While in case of matrix microcapsules increase in the amount of SAL in W 1 phase and concentration of the coating polymer in organic phase led to increase in DEE of the matrix microcapsules and considerable decrease in the drug release in both SGF and SIF. No interaction between the drug and any of the polymers used to prepare microcapsules was evident from Fourier transform infra-red (FTIR) analysis. The matrix microcapsules prepared using higher concentration of SAL and PMMA released the drug following zero order or Case-II transport model. The matrix microcapsules appeared to be suitable for releasing lesser amounts of DFS in SGF and providing extended release in SIF.
2011
The objective of the present study was preparation and invitro evaluation of sustained release microsp heres of aceclofenac. Generally administration of microspher es will provide the localization of active substanc e at the site of action for prolonged period of the time. The micros pheres of aceclofenac was prepared by emulsion cross linking method and solvent evaporation technique by using different grades of gelatin with varying concentra tions and Eudragit (S-100,L-100) polymers respectively. The f ormulations were evaluated for particle size distri bution analysis, flow properties like Angle of repose, bul k density, tapped density, true density, Hausner’s Ratio, Carr’s index, microencapsulation efficiency, Scanning elec tron microscopy(SEM) and invitro release studies. T he optimized formulation showed good invitro sustained release activity of the drug Aceclofenac.