Stability of cefazolin sodium, cefoxitin sodium, ceftazidime, and penicillin G sodium in portable pump reservoirs

The stability of cefazolin sodium, cefoxitin sodium, ceftazidime, and penicillin G sodium in prefilled drug reservoirs that were stored at -20 degrees C for 30 days, thawed at 5 degrees C for four days, and pumped at 37 degrees C for one day was studied. Each antimicrobial agent was diluted with sterile water for injection to a concentration representative of the most common dosage when administered via a portable infusion pump. Ten milliliters of each drug solution was placed in individual glass vials to serve as controls, and volumes appropriate to deliver the designated dosages were loaded into the drug reservoirs. Triplicate reservoirs were prepared for each drug. One-milliliter samples from all containers were taken on days 0, 30, 31, 32, 33, 34, 34.5, and 35. All solutions were observed for color change and precipitation. Drug concentrations were determined using high-performance liquid chromatography. Leaching of the plasticizer diethylhexyl phthalate (DEHP) was analyzed by packed-column gas chromatography on days 0 and 35. No color change or precipitation was observed. No DEHP concentrations above 1 ppm were detected. More than 90% of the initial concentrations of each drug remained, except penicillin G sodium, which had a mean concentration of 83.9 +/- 0.5% at the end of the study. Cefazolin sodium, cefoxitin sodium, and ceftazidime in admixtures with sterile water for injection are stable under the conditions of this study. Penicillin G sodium should not be administered for more than 12 hours after such a cycle of freezing and thawing.     

Stability of ceftazidime (with arginine) and of cefuroxime sodium in infusion-pump reservoirs.

The stability of ceftazidime (with arginine) and cefuroxime sodium was studied after storage in infusion-pump reservoirs at freezing and refrigerated temperatures and subsequent simulated administration over 24 hours at near-body temperature. Polyvinyl chloride reservoirs and glass vials were filled with ceftazidime (with arginine) or cefuroxime sodium at various concentrations, diluted in sterile water. Three reservoirs each of ceftazidime 30 and 60 mg/mL and of cefuroxime 22.5, 30, 45, and 60 mg/mL were stored for various times and at various temperatures. Three glass vials each of ceftazidime or cefuroxime 30 and 60 mg/mL were stored for 30 days at -20 degrees C, followed by 4 days at 3 degrees C and 24 hours at 30 degrees C. Samples obtained periodically during storage and during simulated administration were analyzed with high-performance liquid chromatography. Both drugs maintained at least 90% of their initial concentration under all of the test conditions except simulated administration at 30 degrees C, during which degradation accelerated. In portable infusion-pump reservoirs, ceftazidime 30 and 60 mg/mL and cefuroxime 30 and 60 mg/mL were stable for 30 days at -20 degrees C followed by 4 days at 3 degrees C; ceftazidime 30 and 60 mg/mL was stable for 10 days at 3 degrees C; and cefuroxime 22.5 and 45 mg/mL was stable for 7 days at 3 degrees C. However, the drugs may need to be administered over less than 24 hours when the pump reservoir is worn on the patient's body.     

Stability of fentanyl citrate in 0.9% sodium chloride solution in portable infusion pumps

The stability of fentanyl citrate diluted with 0.9% sodium chloride injection for use in portable infusion pumps was studied. The commercially available injection containing 50 micrograms of fentanyl per milliliter was diluted to a concentration of 20 micrograms/mL. Twelve 100-mL portions of the dilute solution were placed in polyvinyl chloride infusion pump drug reservoirs; six were stored at 3 degrees C and six at 23 degrees C; three at each temperature were overwrapped with polypropylene-Mylar. Initially and after 5, 10, 20, and 30 days of storage, 1-mL samples were taken from each reservoir, inspected for color change and precipitation, and assayed for fentanyl concentration by high-performance liquid chromatography. Initially and on day 30, pH of the samples was checked. No precipitation or change in color or pH was observed. No substantial decrease in fentanyl concentration was found in either the wrapped or unwrapped samples at either temperature, although concentrations on day 30 in the samples at 23 degrees C were slightly lower than those at 3 degrees C. Under the conditions studied, fentanyl citrate solutions containing 20 micrograms of fentanyl per milliliter can be stored for 30 days in polyvinyl chloride reservoirs for portable infusion pumps.     

Development of raft-forming liquid and chewable tablet formulations incorporating quercetin solid dispersions for treatment of gastric ulcers

Gastroretentive raft-forming formulations were developed in liquid and chewable tablet dosage forms to achieve prolonged delivery of quercetin in the stomach. The formulations contained a solid dispersion of quercetin and polyvinylpyrrolidone (PVP K 30) at a 1:10 w/w ratio to improve the solubility of the flavonoid. The formulations also contained sodium alginate as a gel forming agent, calcium carbonate as a calcium source and carbon dioxide producer and hydroxypropyl methylcellulose K100M as a drug release retarding polymer. The chewable tablets incorporated mannitol as a diluent. Both liquid and chewable tablet formulations exhibited rapid floating behaviour (lag time < 1 min) and long floating duration (>24 h) in 0.1 N HCl. The optimized liquid formulation showed superior characteristics based on high raft strength (10.4 g) and sustained release of quercetin (93 % over 8 h) whereas the optimized chewable tablet formulation exhibited lower raft strength (7.2 g) and lower drug release (79 % in 8 h). The optimized liquid and chewable tablet formulations were found to induce anti-inflammatory activity in cell culture using RAW 264.7 cells macrophages and enhance the migration of human gastric adenocarcinoma (AGS) epithelial cells in vitro, indicating wound healing potential for treatment of gastric ulcers.     

Stability of ondansetron hydrochloride in portable infusion-pump reservoirs.

The stability of ondansetron hydrochloride 0.24 and 2 mg/mL when delivered by portable infusion pump at near-body temperature over various time periods was investigated. Nine 100-mL drug reservoirs were prepared, three containing ondansetron hydrochloride 2 mg/mL and six containing ondansetron hydrochloride diluted with 0.9% sodium chloride injection to 0.24 mg/mL. Three of the reservoirs containing the diluted solution were refrigerated for up to 30 days at 3 degrees C before being attached to portable infusion pumps and pumped over 24 hours at 30 degrees C. The remaining six reservoirs were attached to pumps immediately after being filled, and the solutions were delivered for up to 24 hours (the diluted solution; three reservoirs) or up to seven days (the concentrated solution; three reservoirs) at 30 degrees C. Samples were taken initially and periodically and analyzed by high-performance liquid chromatography and with a pH meter. Both the diluted and the concentrated solutions of ondansetron hydrochloride retained at least 95% of the initial drug concentration under all the conditions studied. There was no appreciable change in pH. Ondansetron hydrochloride 0.24 mg/mL was stable when stored for up to 30 days at 3 degrees C and infused over 24 hours at 30 degrees C. Ondansetron hydrochloride 2 mg/mL was stable when infused for up to one week at 30 degrees C.     

The effect of formulation vehicles on the in vitro percutaneous permeation of ibuprofen

Background

The transdermal application of substances represents an elegant approach to overcome side effects related to injections or oral treatment. Due to benefits like a constant plasma level, no pain during application and a simple therapeutic regime, the optimization of formulations for transdermal drug delivery has gained interest in the last decades. Ibuprofen is a non-steroidal anti-inflammatory compound which is nowadays often used transdermally. The objective of this work was to conduct a study on the effect of different 5% ibuprofen containing formulations (Ibutop^? cream, Ibutop^? gel, and ibuprofen solution in phosphate buffered saline) on the in vitro-percutaneous permeation of ibuprofen through skin to emphasise the importance of the formulation on percutaneous permeation and skin reservoir.

Methods

The permeation experiments were conducted in Franz-type diffusion cells according to OECD guideline 428 with 2 mg/cm² ibuprofen formulation on each skin sample. Ibuprofen was analysed in the receptor fluid and extracted skin samples by UV-VIS high-performance liquid-chromatography at 238 nm. The plot of the cumulative amount of ibuprofen permeated versus time was employed to calculate the apparent permeability coefficient, the maximum flux and the lagtime, all of which were statistically analysed by One-way ANOVA.

Results

Although ibuprofen permeation out of the gel increases rapidly within the first four hours, the cream produced the highest ibuprofen delivery through the skin within 28 hours, followed by the solution and the gel. A significant shorter lagtime was found after gel treatment compared with the cream and the solution. After 28 hours 59% of the applied ibuprofen was found in the receptor fluid of the cream treated samples, 26% in the solution treated samples and 21% in the samples treated with the gel. Fourfold higher ibuprofen reservoirs were found in the solution and gel treated skin samples compared to the cream treated skin samples.

Conclusion

The present study demonstrates the importance of the formulation on transdermal drug delivery of ibuprofen and emphasises the differences of drug storage within the skin due to the formulation. Thus, it is a mistaken assumption that formulations comprising the same drug amount are equivalent regarding skin permeability.     

Preparation of a novel floating ring capsule-type dosage form for stomach specific delivery

Study objectives were to develop a unique floating ring capsule dosage form which combines gastric soluble and insoluble portions, and to evaluate its suitability for stomach specific drug delivery. New floating ring capsules were developed using different polymers and were compared for various parameters. The formulation with HPMC and sodium CMC has better floating properties. The effects of polymers concentration on drug release were studies by in vitro release studies. The interaction studies of combined drug with polymers were determined using FT-IR spectroscopy. The entrapped air within the gel barrier and lower densities of HPMC and sodium CMC resulted in better floating behavior. Steady slow gel formations showed prolonged drug release. The in vitro release rates were generally found to be faster with low concentration of carbopol showing release within 2 h, while formulations containing high amount of HPMC showed release in 8 h. In particular, the higher concentration of HPMC formulation shows the best drug release performance. A very low change in peak shift was observed only with sodium alginate formulations. Further, FT-IR measurements confirmed the absence of any chemical interactions. Results indicate that new floating ring capsule is a promise dosage form for stomach specific delivery.     

Stability of ceftazidime and amino acids in parenteral nutrient solutions

The stability of ceftazidime was studied under conditions simulating administration via a Y-injection site into a primary infusion of parenteral nutrient (PN) solution; the stabilities of ceftazidime and amino acids when the drug was added directly to PN solutions were also studied. Three PN solutions containing 25% dextrose were used; the amino acid contents were 0, 2.5%, and 5%. Ceftazidime with sodium carbonate was used to prepare stock solutions of ceftazidime 40 mg/mL in both 0.9% sodium chloride injection and 5% dextrose injection; to simulate Y-site injection, samples were added to the three PN solutions to achieve ceftazidime concentrations of 10 and 20 mg/mL, or 1:1 and 1:3 ratios of drug solution to PN solution. Samples of these admixtures were assayed by high-performance liquid chromatography (HPLC) initially and after room-temperature (22 degrees C) storage for one and two hours. Additional solutions were prepared by adding sterile water for injection to ceftazidime with sodium carbonate; drug solutions were added to each PN solution in polyvinyl chloride bags to achieve ceftazidime concentrations of 1 and 6 mg/mL. The samples were assayed by HPLC for ceftazidime concentration after storage at 22 degrees C for 3, 6, 12, 24, and 36 hours and at 4 degrees C for 1, 3, 7, and 14 days. Amino acid stability was analyzed in admixtures containing 5% amino acids and ceftazidime 6 mg/mL after 24 and 48 hours at 22 degrees C and after 7 and 10 days at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)     

The physicodynamic properties of mucoadhesive polymeric films developed as female controlled drug delivery system

Phenoporlamine hydrochloride is a novel compound that is used for the treatment of hypertension. The purpose of this study was to develop a sustained release tablet for phenoporlamine hydrochloride because of its short biological half-life. Three floating matrix formulations of phenoporlamine hydrochloride based on gas forming agent were prepared. Hydroxypropyl methylcellulose K4M and Carbopol 971P NF were used in formulating the hydrogel drug delivery system. Incorporation sodium bicarbonate into matrix resulted in the tablet floating over simulated gastric fluid for more than 6 h. The dissolution profiles of all tablets showed non-Fickian diffusion in simulated gastric fluid. Moreover, release of the drug from these tablets was pH-dependent. In vivo evaluations of these formulations of phenoporlamine hydrochloride were conducted in six healthy male human volunteers to compare the sustained release tablets with immediate release tablets. Data obtained in these studies demonstrated that the floating matrix tablet containing more Carbopol was capable of sustained delivery of the drug for longer periods with increased bioavailability and the relative bioavailability of formulation (containing 25% Carbopol 971P NF, 8.3% HPMC K4M) showed the best bioequivalency to the reference tablet (the relative bioavailability was 1.11 ± 0.19).     

Drug delivery systems. 4. Implants in drug delivery

In comparison with many of the other drug delivery systems, implantable pumps and implants for variable rate delivery are at a crude stage of development. Although exceptions exist, the typical implantable pump consists of an electromechanically complex mechanism to regulate drug delivery from a percutaneous refillable reservoir, while power to drive the system comes from a transcutaneous energy transmission system. The potential for electrical or mechanical failure is high, and the systems are not yet sufficiently convenient or easy to use to recommend in a routine therapy. Problems with refilling of an apparently well designed implanted reservoir have been observed while, at the same time, cutaneous energy transmission systems are not well established. In most instances, the development of an elementary osmotic pump system dosage form follows a well defined path of physical-chemical formulation and clinical testing. The benefits most often provided by the dosage form are expected to be (1) increase in selectivity of drug action achieved by the system's zero-order release rate, and (2) decrease in frequency of administration. The success in achieving these values is quantifiable from the pharmacology of the drug substance and its pharmacokinetics. Osmotic and other technical approaches to producing economical, rate-controlled dosage forms will make it possible for all new pharmaecutical products to carry kinetic specification of rate as well as static specification of content. This review considers the characteristics of the ideal implantable pump, the clinical situations which require pumps, the limitations of portable pumps, and the detailed characteristics of existing implantable pumps and implants. Most of the review, however, focuses on insulin delivery because of the importance of this subject.     

Stability of cefotaxime sodium and metronidazole in an i.v. admixture at 8 degrees C

The stability of cefotaxime and metronidazole in i.v. admixture at 8 degrees C was studied. The commercially available injectable formulation of cefotaxime sodium 1 g was diluted to 5 mL with 0.9% sodium chloride injection and added to metronidazole injection 500 mg/100 mL. A 2-mL sample was removed and diluted to 100 mL with water. Thirty 1-mL portions were transferred to glass vials and refrigerated at 8 degrees C. At 0, 1, 2, 4, 8, 12, 24, 36, 48, and 72 hours after the admixture was prepared, the vials were removed, placed in a refrigerated autosampler, and assayed for cefotaxime and metronidazole concentrations by stability-indicating high-performance liquid chromatography. Over the 72-hour study period, the concentration of cefotaxime remaining at all assay times was 95.91-101.13% of the initial concentration. The concentration of metronidazole remaining at each assay time was 93.08-102.19% of the initial concentration. Cefotaxime sodium 10 mg/mL and metronidazole 5 mg/mL were stable for 72 hours at 8 degrees C in an i.v. admixture prepared from commercially available injectable formulations.     

Peptide drug delivery strategies for the treatment of diabetes

Drug delivery strategies for diabetes have included a wide range of scientific and engineering approaches, including molecular design, formulation and device design. Molecular engineering has resulted in modified pharmacokinetics, such as rapid-acting or slow-release analogs of insulin. Long-acting insulin formulations are designed to meet the body's basal needs, whereas rapid-acting insulin formulations are designed to cover mealtime glucose spikes. Furthermore, the discovery of new therapeutic biomolecules, which like insulin need to be injected, will drive the need for more flexible and universally applicable delivery systems. Formulation design, such as particle engineering, can be used to modify pharmacokinetic profiles. In general, suspension formulations of insulin commonly demonstrate reduced solubility and result in sustained release. Similarly, depot injections can result in precipitation of insulin at the site of injection, again resulting in lower solubility and sustained release. Particle engineering also has been applied to pulmonary formulations for delivery to the deep lung. The creation of novel drug delivery methods for the treatment of diabetes should remove barriers to insulin therapy and increase patient acceptance and compliance. Eliminating routine injections with needle-free injectors, insulin pumps, inhalation, buccal sprays, intra-nasal delivery, and transdermal patches may offer increasingly attractive alternatives.     

Thiolated Chitosans: Design and In Vivo Evaluation of a Mucoadhesive Buccal Peptide Drug Delivery System

Purpose Intravenous application of pituitary adenylate cyclase-activating polypeptide (PACAP) has been identified as a promising strategy for the treatment of type 2 diabetes. To generate a more applicable formulation, it was the aim of this study to develop a sustained buccal delivery system for this promising therapeutic peptide. Methods 2-Iminothiolane was covalently bound to chitosan to improve the mucoadhesive and permeation-enhancing properties of chitosan used as drug carrier matrix. The resulting chitosan–4-thiobutylamidine conjugate was homogenized with the enzyme inhibitor and permeation mediator glutathione (gamma-Glu-Cys-Gly), Brij 35, and PACAP (formulation A). The mixture was lyophilized and compressed into flat-faced discs (18 mm in diameter). One formulation was additionally coated on one side with palm wax (formulation B). Tablets consisting of unmodified chitosan and PACAP (formulation C) or of unmodified chitosan, Brij 35, and PACAP (formulation D) served as controls. Bioavailability studies were performed in pigs by buccal administration of these test formulations. Blood samples were analyzed via an ELISA method. Results Formulations A and B led to an absolute bioavailability of 1%, whereas PACAP did not reach the systemic circulation when administered via formulations C and D. Moreover, in the case of formulations A and B, a continuously raised plasma level of the peptide drug being in the therapeutic range could be maintained over the whole period of application (6 h). Formulations A and B were removed by moderate force from the buccal mucosa after 6 h, whereas formulations C and D detached from the mucosa 4 h after application. Conclusion The study reveals this novel mucoadhesive delivery system to be a promising approach for buccal delivery of PACAP.     

Fortum stability in different disposable infusion devices by pyridine assay

The stability of ceftazidime in 5% dextrose injection and 0.9% sodium chloride injection when stored in a different disposable infusion device was determined. Solutions of ceftazidime 40 mg/ml were used to fill the drug administration devices. Stability was determined for both 5% dextrose injection and 0.9% sodium chloride injection solutions at 37 °C in four disposable infusion devices. Ceftazidime and its mean degradation product, pyridine, were simultaneously assayed in triplicate by a stability-indicating high-performance liquid chromatographic (HPLC) method. This method was simple, sensitive (limit of quantitation (LOQ), 2 ng injected for both compounds), rapid (run time was 7 min) and precise (mean recovery was 100.5±2.9 and 103.6±1.9% for pyridine and ceftazidime, respectively). The ceftazidime stability in the 5% dextrose solution was lower than in the 0.9% sodium chloride solution. When stored at 37 °C in a disposable infusion device, the stability of the ceftazidime is included in large hourly range, depending strongly on the manufacturer. The stability of ceftazidime exceed 19 h in none studied cases. The pyridine formed in 24 h was in the range of 100–400 mg depending on devices and infusions.     

Long-term stability of 5-fluorouracil stored in PVC bags and in ambulatory pump reservoirs

Prolonged infusions of 5-fluorouracil (5FU) have been used since the early 1960s, but recently there has been a major resurgence of interest, partly because of the advent of electronically controlled portable infusion pumps. Admixtures of new formulation 5FU were subjected to stability studies to establish the feasability of continuous infusions. In the first study, the stability of 5FU, 1 or 10 mg ml⁻¹, was determined in poly(vinyl chloride) (PVC) bags (0.9% sodium chloride injection or 5% dextrose injection) at 4 and 21°C after storage for 0, 1, 2, 3, 4, 7 and 14 days. In the second study, the stability of undiluted 5FU was tested at different temperatures (4 or 33°C) in ethylene vinyl acetate (EVA) or PVC ambulatory pump reservoirs after storage for 0, 3, 5, 7 and 14 days. For each condition, samples from each admixture were tested for drug concentration by stability-indicating high-performance liquid chromatography. The admixtures were also monitored for precipitation, colour change and pH. Evaporative water loss from the containers was measured. The stability of 5FU in PVC bags was unaffected by 14 days of storage at either 4 or 21°C. When stored in EVA reservoirs, 5FU was stable for at least 2 weeks at 33°C and for 3 days at 4°C (a precipitate was observed after 3 days). In PVC reservoirs, 5FU was stable for over 14 days at 33°C, but at 4°C a precipitate appeared after 5 days. Loss of water through the reservoirs was substantial only at 33°C for 14 days, and gave falsely high readings.     

Ion-activated In Situ Gelling Ophthalmic Delivery Systems of Azithromycin

Gelation of pectin caused by divalent cations especially calcium ions has been applied to develop an ophthalmic formulation of azithromycin in the present study. Rapid elimination of drug on instillation into cul de sac would be minimal with in situ gelling ophthalmic solution leading to increased precorneal contact time and prolonged drug delivery. In the formulation development studies pectin was used in different concentrations (1-5% w/v) and different proportions of the hydrocolloids hydroxypropyl methylcellulose and sodium carboxymethyl cellulose of different grades of viscosity were used. The primary criteria for formulation optimization were gelling capacity and rheological behaviour. In addition, formulations were evaluated for pH, and antimicrobial efficacy and drug release. The clarity, pH, gelation in simulated tear fluid and rheological properties of the optimized formulations were satisfactory. The formulations inhibited the growth of Staphylococcus aureus effectively in cup–plate method and were proved to be safe and non irritant on rabbit eyes. The results indicate that pectin based in situ gels can be successfully used to prolong the duration of action of azithromycin.     

Enteric‐coated solid dosage forms containing sodium bicarbonate as a drug substance: an exception from the rule?

Sodium bicarbonate (sodium hydrogen carbonate) is used as an oral medication in disorders such as mild metabolic acidosis and chronic kidney disease. The two commercial products on the German market, bicaNorm and Nephrotrans, and also newly developed multiple-unit pellet formulations, have been characterized in these investigations by in-vitro methods like disintegration and dissolution testing. Both marketed products containing sodium bicarbonate are of sufficient pharmaceutical quality according to the European Pharmacopoeia. However, they and the novel pellet preparations showed different drug release at moderately elevated pH values. Early drug release may cause dose dumping in the stomach and adverse drug effects from the developed carbon dioxide. The soft capsule preparation (Nephrotrans) released the smallest amount of sodium bicarbonate at pH 1 and 4.5 of all formulations tested. It appeared that oral dosage formulations of sodium bicarbonate were an exception to the rule: the monolithic soft capsule seemed to be superior to an enteric-coated tablet as well as to multiple-unit pellet formulations from the biopharmaceutical point of view. Our results correspond with individual reports on adverse effects from patients treated with the sodium bicarbonate products.     

Design of submicron and nanoparticle delivery systems using supercritical carbon dioxide-mediated processes: an overview

Supercritical carbon dioxide technology is an environmentally benign technique that allows precise control of particle morphology, while minimizing organic solvent use for a wide variety of biomedical and pharmaceutical applications. Supercritical carbon dioxide processes have benefits over the conventional particle formation methods in terms of improved control, flexibility and operational ease. This article gives an insight into a variety of supercritical fluid techniques relevant to drug formulation, recent advances and novel applications in the field of controlled delivery. These new methods have been designed to alleviate the scaling-up of the traditional methods for nanoparticle formulation either in the form of polymeric scaffolds, impregnation or nanoencapsules using a simple one-step process to produce micron-size particles.     

Solution stability of cephradine neutralized with arginine or sodium bicarbonate

The solution stability of two formulations of cephradine--one using L-arginine and the other sodium carbonate as the neutralizer--was studied. Solutions of each formulation of 1% cephradine were prepared in the following diluents: 0.9% sodium chloride injection, lactated Ringer's injection, Ringer's injection, Normosol-R injection, 5% dextrose injection, and sterile water for injection; 5 and 25% solutions were made with sterile water for injection. All solutions were maintained at 25 degrees C, and at least five samples of each were assayed at various time intervals. Assay methods were HPLC, hydroxylamine colorimetric assay, microbiological agar diffusion, and iodometric analysis. By all assay methods, degradation rates of 1% solutions were lower for the arginine-neutralized product than for the one neutralized with sodium carbonate. This may be attributable to the lower pH values of solutions of the formulation with arginine, because one mechanism of degradation is pH-dependent. At concentrations of 5%, the difference in cephradine stability between the two formulations was minimal. At the 25% concentration, the formulations containing sodium carbonate were more stable. At these higher concentrations, the effect of pH is less important because degradation occurs by a combination of mechanisms. The 1% cephradine-arginine formulation was more stable than the same strength cephradine-sodium carbonate formulation in all the i.v. diluents studied. At 5 and 25% cephradine concentrations, the differences in stability between the two formulations were not substantial.     

Development of enzyme-controlled colonic drug delivery using amylose and hydroxypropyl methylcellulose: optimization by factorial design

The aim of the present study is to develop colon-targeted drug delivery systems for diclofenac sodium which release the drug specifically and instantly at target site using amylose as a carrier. Coating formulations were designed based on the full factorial design. The evaluated responses were lag time prior to drug release and T90. Compression-coated tablets of diclofenac sodium containing various proportions of amylose and HPMC were prepared. In vitro drug release studies were done by changing pH method with enzyme. In vivo studies were done to confirm the potential of formulation to release the drug at target site. The dissolution data revealed that the ratio of polymers is very important to achieve optimum formulation. Results showed that the tablet prepared according to the above formulation released drug instantly at pH 6.8 (simulating colonic pH). An in vivo study shows that optimized formulation disintegrated in the target region. The results of this study revealed that factorial design is a suitable tool for optimization of coating formulations to achieve colon delivery. It was shown that coating formulation consisting of amylose 285 mg and HPMC 150 mg coating has the potential for colonic delivery of diclofenac sodium irrespective of change in pH in a patient with IBD.