Current Issue : April - June Volume : 2012 Issue Number : 2 Articles : 12 Articles
Crystal engineering has been identified by pharmaceutical scientists as a means of improving and tailoring the physicochemical properties of active pharmaceutical ingredients (API). The properties of an API may be modified through salt formation using a limited number of available counter ions. Co-crystals offer further potential for changing the API properties by using a much more extensive range of co-crystallizing molecules (co-builders). A pharmaceutical co-crystal contains API with excipients or other APIs. It is important to note that co-crystals are a homogeneous phase of stoichiometric composition and not a mixture of pure component crystalline phases. Co-crystals possess tremendous uplifting properties compared to normal crystals like enhancement of bio-availability, solubility19, stability. The present article deals with various aspects of co-crystal fabrication, pharmaceutical application, and various patented technologies related to co-crystallization....
The objective of the work is to evaluate the suitability of natural excipients banana powder and treated agar as disintegrant in orally disintegrating tablets (ODT). For the study purpose formulations were prepared by varying concentrations of these natural excipients and subjected to pre- and post-compression evaluations. Tablets were punched by direct compression technique. Similarity factor and dissolution efficiency methods are applied in this study for more accurate dissolution profile comparison. Pre-compression evaluation revealed that formulations containing treated agar showed excellent flow properties and compressibility than formulations with banana powder. Post compression evaluation shows increase in disintegration time and wetting time and low water absorption ratio for formulations containing banana powder than formulations containing treated agar. Dissolution profile of formulations containing treated agar showed good similarity with marketed formulation than formulations with banana powder. Treated agar when used at concentration of 40 % showed best results. It is concluded from the study that treated agar was more suitable to use as disintegrant in ODT formulations and it was also proved as a good natural excipient....
The aim of this study was to formulate ketoprofen microsponges by emulsion solvent diffusion method and formulation of hydrogel containing ketoprofen microsponges. The prepared microsponges were found to be discrete, spherical particles and were free flowing with particle size range of 58.9 to 89.5 µm. Microsponge with maximum drug entrapment was selected and formulated into hydrogel using carbopol 934 and sodium CMC as gelling agents. The formulated hydrogels were found transparent and smooth. All the gel formulations showed good homogeneity with absence of lumps. The hydrogel formulations exhibited sustained drug release in pH 7.4 phosphate buffer. The In-vitro release for all the prepared gel formulations fitted best to first order and matrix model that confirmed that mechanism of drug release was found to be diffusion process. The prepared gel formulations does not show any changes in physical appearance and no significant variation in pH and drug content was observed in accelerated stability studies....
The objective of this study was to develop sustained release matrix tablets of Metoprolol Succinate (MS) for oral delivery using Poly ethylene oxide (PEO) blended with other polymers such as Xanthan gum, Eudragit, Hydroxypropyl cellulose (HPC) & Hydroxy ethyl cellulose (HEC). Matrix tablets were prepared by Direct compression & wet granulation to fabricate drug containing polymeric granules in polymeric matrix after which they were characterized for physical characteristics. The effect of process variables such as; method of preparation, blending of PEO with other polymers, effect of adding diluent, drug loading, stirring speed , the effect of addition of HPMC K-100 and addition of electrolyte along with PEO as extra granular polymer on the release profile of drug was also evaluated. The drug- polymer interaction studies were performed by FTIR. The drug release data were analyzed by zero order, first order, Higuchi and Peppas equations. Finally it was concluded that by using proper combination of polymers, diluents & drug loading, Sustained release (SR) matrix tablet of MSsuitable for once a day could be easily prepared & commercialized....
Solid dispersion is a unique approach to enhance the solubility and dissolution rate of poorly water soluble drugs. The purpose of the present study was to enhance the dissolution rate of simvastatin (SIM), a practically water insoluble drug by preparation of solid dispersion using a hydrophilic carrier, poloxamer 188 (PXM). The solid dispersions of simvastatin were prepared using techniques such as co-grinding, kneading and solvent evaporation. All the solid dispersions showed an increase in the dissolution rate of simvastatin but the solid dispersion prepared by kneaded method exhibited best dissolution profile. The x-ray diffraction and scanning electron microscopy studies demonstrated that enhanced dissolution of SIM from kneaded solid dispersions might be due to decrease in crystallinity of SIM. The kneaded solid dispersions were formulated into tablets using superdisintegrant Ac-di- sol. Dissolution studies of the tablets were carried out in phosphate buffer pH 6.8. Findings of this study showed that dissolution enhancement of SIM was obtained by preparing its solid dispersions with PXM using kneaded technique....
The primary purpose of this research work was to prepare a gastroretentive drug delivery system of lansoprazole. Formulation trials were carried out using natural and synthetic swelling polymers like guar gum, xanthan gum and HPMC K4M for ascertaining the best possible polymer for further studies. The effects of citric acid and stearic acid on drug release profile and floating properties were also investigated. The addition of stearic acid reduced the drug dissolution due to its hydrophobic nature. Among the three polymers HPMC K4M showed better results and found to be suitable for floating delivery device. The amount of HPMC K4M and stearic acid were found to significantly influence all in-vitro response parameters. So, optimization was carried out by using central composite design by taking HPMC K4M and stearic acid as independent variables and floating lag time, % drug release for 3 h, % drug release for 8 h as dependent variables respectively. The optimized formulation released 92 % drug release upto 8 h. The swelling index in 5 h and floating lag time were found to be 56 % and 9 sec respectively. The results of pre-compression and post-compression parameters of all the formulations were found to be within the limits. Accelerated stability studies of the optimized formulation indicated no appreciable change in the drug content and in-vitro drug release rates of formulation. Thus, with using optimum concentrations of HPMC K4M and stearic acid the floating tablet of lansoprazole was successfully developed for sustained action....
The aim of present work is to provide transdermal delivery of rasagiline provides more beneficial drug delivery over oral drug delivery system. Transdermal patch offer the advantages such as maintenance of controlled and prolong drug level, reduced frequency of dosing, minimization of inter and intrapatient variability, self administration, and easy termination of medication during treatment due to side effects observed leading to patient compliance, directly systemic delivery prevent drug related side effects. Rasagiline transdermal patch made from different types of pressure sensitive polymers like acrylic adhesive, polyisobutylene adhesive and silicon adhesives. It was evaluated a combination of pressure sensitive adhesive to optimize skin permeation and physical property of rasagiline patch. It was found that silicone type PSA formulation has zero order release pattern. Physical properties of different formulations were evaluated in terms of peel, tack and shear. All formulations were stable during 28 days study and reflects physical stability of formulations. Combination of silicone PSAs has better physical property and controlled drug release profile. A combination of silicon type pressure sensitive adhesive can be use to prepare stable formulation of rasagiline with zero order controlled release profile....
The aim is to formulate non effervescent gastroretentive floating drug delivery of Celecoxib that would retain the drug in stomach and continuously release the drug in a controlled manner in a predetermined time proposed leading to improved bioavailability. The selection of polymer which is able to release the drug in controlled fashion with initial burst, release of drug to initial therapeutic level quickly. Solvent evaporation was used to prepare the microparticulates and evaluated for buoyancy, density, particle size, SEM, in vitro dissolution, in vitro permeation and in vivo studies. Densities of microparticulates were found less than the density of gastric fluid. In vitro release followed diffusion with Higuchi spherical matrix release and ‘n’ value suggested non-Fickian diffusion. Ethylcellulose microparticulates demonstrated initial rapid drug release followed by prolonged phase. In vitro permeation of all microparticulates followed zero order and the mechanism was confirmed by ‘n’ value, suggested super case II transport mechanism. Microparticulates showed excellent stabilityand the in vivo Anti-Inflammatory studies hold promising results for management of inflammation 12 hours. Present investigation holding the novel and promising results to prove a suitable sustained release floating drug delivery system....
Aceclofenac is a non-steroidal anti-inflammatory drug used for treatment of pain and inflammation. The short biological half-life (4 h) and dosing frequency more than once daily make aceclofenac a suitable candidate for sustained release formulations. Sustained release lipospheres of aceclofenac were prepared using cetyl alcohol and Compritol 888 ATO. The prepared lipospheres were characterized for their percentage yield, encapsulation efficiency, particle size, surface morphology, micromeritic properties and in-vitro release over 24 hours. The optimum formula was incorporated into a lyophilized system to produce sustained release orally disintegrating tablet (SR-ODT), which intended to disintegrate rapidly within the mouth into lipospheres that will deliver aceclofenac in sustained release manner after swallowing. The prepared SR-ODTs were evaluated regarding weight variation, friability, content uniformity, disintegration, in-vitro release and in-vivo pharmacokinetics in albino rabbits. All the prepared lipospheres showed satisfactory results regarding the investigated properties. According to the in-vitro release data, formula FI (prepared using cetyl alcohol at lipid: drug ratio of 1:1 and 0.5% PVA) was selected as the optimum formula, and thus, used for preparation of the SR-ODT. The prepared SR-ODT demonstrated acceptable weight variation, friability and content uniformity. Also, the SR-ODT showed rapid in-vitro disintegration time (10 s) and it was successful in sustaining drug release up to 24 hours. The results of pharmacokinetic studies showed that the SR-ODT exhibited longer MRT and lower Cmax when compared with the values of the commercial brand of aceclofenac immediate release tablet (Bristaflam®), confirming our target in the preparation a sustained release formula....
A novel approach of drug delivery system is towards pulsatile-release pattern. Pulsatile drug delivery is one such system that, deliver drug at the right time, right place and in right amounts, holds good promises of benefit to the patients. This system is receiving increasing interest for the development of drugs whose conventional controlled drug-release systems with a continuous release are not satisfactory. This system can be classified in multiple-pulse and single-pulse systems. A popular class of single-pulse systems is that of rupturable dosage forms other systems consist of a drug-containing core, covered by a swelling layer and an outer insoluble, but semi permeable polymer coating or membrane. Pulsatile drugs involve controlled drug-release systems with a continuous release at distinct time intervals that are programmed into the drug product. Since some diseases have a predictable cyclic rhythm, the timing of medication regimens can improve the outcome of a desired effect. This condition demands development of pulsatile drug delivery system. Thus a focus on the diseases requiring Pulsatile Drug Delivery System, methodologies involved for the existing systems, recent update and Pulsatile Drug Delivery system product has a vital importance....
This study was aimed to develop a polymeric drug delivery system for controlling the ocular delivery of ofloxacin. To achieve this goal, Ofloxacin-loaded (poly D, L-Lactide (DL-PLA) nanoparticles (NPs) were prepared by solvent diffusion technique. The 2*32 full factorial experimental design was used to study the influence of three different independent variables (drug to polymer ratio, surfactant type and surfactant concentration) on two responses: particle size and encapsulation efficiency. Analysis of variance (ANOVA) was used to evaluate the significance of the difference between the tested factors using computer software Stat View version 4.57. The physicochemical characteristics of DL-PLA nanoparticles were evaluated using particle size analyzer, scanning electron microscopy, differential scanning calorimetry and X-ray diffractometry. All independent variables were found to significantly influence the particle size and the entrapment efficiency. The nanoparticles formulations showed particle size diameter in the range of (200+3.92 – 860+4.32 nm) and a drug loading percent in the range of (23.53+ 1.61 – 44.43+1.11). The in vitro drug release profiles showed half-life (t1/2) up to 7.4 hours indicating the suitability of DL-PLA nanoparticles in controlling Ofloxacin release. The Ofloxacin was released in a biphasic fashion including an initial burst release followed by a sustained release for the next 12 hours. The drug release from all formulae was governed by Fickian diffusion. Based on the statistical model ofloxacin-loaded polymeric nanoparticle suspensions of less than 1µ in size could be produced and that may be of clinical importance as ocular delivery system in treatment of bacterial infection....
The present study explores the effect of chemical penetration enhancers and iontophoresis on the in vitro permeability of lisinopril across excised pig skin. Permeation studies were performed using modified franz diffusion cell. Incorporation of various permeability enhancers like dimethyl sulfoxide, peppermint oil, menthol, oleic acid, sodium louryl sulphate, poly ethylene glycol with pure drug solution showed synergistic effect when combined with iontophoresis that mean it provides an additional driving force to maintain and control the permeability of lisinopril. Steady state fluxes, permeability coefficients, diffusion coefficients, benefits and enhancement ratios by various enhancers were determined. Dimethyl sulfoxide was the most active enhancer, and when combined with iontophoresis it was possible to deliver 44.506±1.210 mmol/cm2 of drug at the end of 8 hours, it was 4.7 times enhancement as compare to delivery of drug without enhancers....
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