Current Issue : April-June Volume : 2010 Issue Number : 2 Articles : 17 Articles
Dry powder inhaler (DPI) formulations predominately use lactose monohydrate as a carrier in the drug carrier blends. Research involving lactose as a carrier for dry powder inhalers (DPIs) represents poor flow properties and penetrates further into the peripheral airways. In addition lactose cannot be used for compounds that interact with the reducing sugar function of the lactose, such as peptides and proteins. Six carriers namely dextrose, lactose, maltitol, mannitol, sorbitol and xylitol were investigated in the present study. The objective of the present work was to explore which carrier would be suitable for better delivery of salbutamol sulphate (SS) from dry powder inhaler. The study was conducted by characterising carriers for their physico-chemical properties and preparing drug/carrier blends with concentration of 5% and 10% drug with the carrier. The mixing uniformity (homogeneity) of the SS in the blends was analysed using spectrophotometer. The blend was then filled into NB7/2 Airmax inhaler device and the deposition profiles of the drug were determined using multi stage liquid impinger (MSLI) after aerosolisation at 4 KPa via the inhaler. The morphology of the carriers conducted using the scanning electron microscope. The results determined that the mean fine particle fraction (FPF) of 5% and 10% blends of dextrose was 48% and mean of 5% and 10% blends of mannitol provided 43%, possibly due to illustrating good flowability and a homogenous formulation. Dextrose exhibited excellent flowability and a homogenous blend. Scanning electron microscope illustrated mannitol with fine elongated particles and dextrose presenting larger and narrow particles. It may be concluded that dextrose could be suitable as a carrier on the basis of its pharmaceutical performance and successful achievement for FPF as a sugar carrier for inhaled drug delivery, as an alternative form to lactose....
Oral drug delivery has been known for decades as the most widely utilized route of administration among all the routes that have been explored for the systemic delivery of drugs via various pharmaceutical products of different dosage forms. Indeed, for sustained-release systems, the oral route of administration has by far received the most attention with respect to research on physiological and drug constraints as well as design and testing of products. This is because there is more flexibility in dosage form design for the oral route than there is for the parenteral route. The goal in designing sustained or controlled-delivery systems is to reduce the frequency of dosing or to increase effectiveness of the drug by localization at the site of action, reducing the dose required, or providing uniform drug delivery. Sustained-release systems include any drug-delivery system that achieves slow release of drug over an extended period of time. If the systems can provide some control, whether this is of a temporal or spatial nature, or both, of drug release in the body, or in other words, the system is successful at maintaining constant drug levels in the target tissue or cells, it is considered a controlled-release system. The present review article focus on various sustained release drug delivery system, its advantages and drawback, factors influencing, mode of action and various evaluation test....
The purpose of this research was to formulate and systematically evaluate the performances of mucoadhesive microspheres of midazolam. Midazolam microspheres containing gelatin alone and gelatin with chitosan were prepared by emulsion cross linking technique using glutaraldehyde as a cross-linking agent. Results of preliminary trials indicate that volume of cross-linking agent, time for cross-linking, polymer-to- polymer ratio and speed of rotation affected characteristics of microspheres. Microspheres were discrete, spherical, and free flowing. The microspheres exhibited good mucoadhesive and also showed high percentage drug entrapment efficiency. The best batch exhibited a high drug entrapment efficiency of 92.0% and a swelling index of 1.24; in vitro bioadhesion was 92.91%. The drug release was also sustained for 12 h. The polymer- to-drug ratio had a more significant effect....
Once an organic compound has been discovered and shown by one scientific group to have some type of desirable pharmacological activity, it will remain a mere curiosity unless a completely different group of scientists incorporate the compound in a formulation that facilitates its activity. The various topics outlined in this brief introduction and overview of the preformulation development of solid dosage forms. A more rational view is that the preformulation stage of drug development is really only half-complete at this stage, and that the program of drug development is not complete until it is fully understood how that API interacts with the excipients that will make up the remainder of its formulation. However, all of this requires a broad basis of understanding regarding the API and its possible interactions with excipients materials and a thorough understanding of the range of excipients required to achieve the pharmacological profile that is sought for the API....
Cyclodextrin (CD) is a degradation product of starch which consists of cyclic oligosaccharide such as alpha, beta, gamma cyclodextrin with different size of cavity. In the area of complexation, cyclodextrin is the best contender where the “guest” molecule remains inside the host molecule. The determination of CD complex is successively achieved by phase solubility profile. Various methods are used to enhance the CD complexation such as Drug ionization, Salt formation, Complex-in-complex, Polymer complexes etc. The drug-cyclodextrin complex is found potential in improving various drug properties like improved solubility and dissolution profile of poorly soluble drugs, enhanced bioavaibility of drugs, improved the stability of drugs. This review article is spotlighted on the applications of and design of various cyclodextrin based novel drug delivery systems like Microspheres, Liposomes, Nanoparticle, Hydrogel, Micelles and Dendrimeres etc....
Dissolution testing has emerged in the pharmaceutical field as a very important tool to characterize drug product performance. Dissolution of a drug depends upon solubility of the drug in that medium and therefore solubility becomes the key determinants for oral bioavailability of the drug. Development of dissolution medium for poorly water soluble drug is critical issue. Dissolution problems with poorly soluble compounds generally fall into two categories. Firstly, extent of release is too low, i.e. one cannot get 100% of the dosage form dissolved and Secondly, rate of release is too slow, i.e. one cannot get dissolution fast enough for a convenient test. In the present work an attempt was made to develop dissolution medium for Silymarin The composition of medium was determined on the solubility data of the drug in different media. Saturation solubility of drug was found to be more in phosphate buffer pH 6.8. The effect of surfactants (sodium lauryl sulphate and Tween 80) in different concentration was studied on solubility of drug in phosphate buffer pH 6.8. The study revealed that phosphate buffer pH 6.8 with various concentration of surfactant doesn’t show any significant enhancement of dissolution as compared to plane phosphate buffer pH 6.8. Hence phosphate buffer pH 6.8 was considered to be a most suitable dissolution medium....
Effect of emulsion forms on the preservative efficacy of phenol, cresol and chlorocresol in formulated oil-water system was evaluated. 1g each of formulated oil-water system was dispersed in 9ml sterile peptone water containing 0.25% Tween 80 to aid solubility of the cream. This was challenged with 0.1ml of 0.5MacFarland standard equivalent overnight grown culture of Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus (all clinical isolates) with 1ml sample of the resulting mixture taken at 0 hr, 6 hr, 12 hr, 24 hr, 7 days, 14 days and 28 days seeded in Mueller-Hinton agar medium and incubated at 37oC for 24 hours. Chlorocresol displayed the best efficacy of all the three phenolic agents tested in all the O/W cream used for the study while the action displayed by the 3 phenolics examined in W/O creams varies with the organism used for the challenge test. Since the activity of the 3 phenolic preservatives differs both in W/O and O/W creams examined, it follows that emulsion type can affect the activity of preservative....
Orlistat also known as tetrahydrolipstatin is a poorly water soluble drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake. Solid dispersion is used to reduce the particle size and to increase the rate of dissolution and absorption. Such as microcrystalline dispersion of poorly soluble drug in matrix consisting of physiologically inert soluble solids such as cyclodextrins as carriers which accommodates poorly water soluble drug like Orlistat. The objective of the present study is to enhance bioavailability by increasing solubility using various techniques such as Kneading method, Fusion method and Trituration method by varying concentration of drug: β-CD. The formulated solid dispersions are evaluated for drug content (98.65%), in- vitro drug release (48%) in water as well as in compendial media. FT-IR, DSC shows presence of drug and absence of interaction between drug and carrier. Thus the solid dispersion formulations could be a promising delivery system for Orlistat with improved solubility, absorption and oral bioavailability....
Fast disintegrating tablets offer an advantage for populations who have difficulty in swallowing. Many fast-disintegrating tablets (FDTs) still face problems of low mechanical strength, poor mouth-feel and higher disintegration times. The purpose of this study is to assess the suitability of spray dried excipient base over direct compression base in the formulation of ODTs of Atenolol (Sparingly aqueous solubility). Spray dried excipient base was prepared using Labultima spray drier. Super disintegrants (such as Ac-Di-Sol, sodium starch glycolate, Kollidon CL), diluent (mannitol) alongwith sweetening agent (aspartame) were used in the formulation of tablets. The tablets were evaluated for angle of repose, hardness, friability, water absorption ratio, disintegration time (DT) and in vitro drug release. Using the same excipients, the tablets were prepared by direct compression and were evaluated in the similar way. Particle size and morphology were compared for both excipient bases. The angle of repose was reduced in spray dried excipient base rather than directly compression base which might be due to increased sphericity of particles indicating that powder is free flowing. The disintegration time and in vitro drug release time were reduced in tablets prepared from spray dried excipient base rather than tablets prepared from direct compression base. Maximum drug release and minimum DT were observed with Kollidon CL excipient base as compared to tablets prepared by direct compression, showing the superiority of the spray dried excipient base technique over direct compression technique....
The aim of the study was to prepare the buccal patches of terbutaline sulphate, the bronchodilator having oral bioavailability of 10.8%, using polymers like sodium alginate, carbopol-934P, PVA, and PVP in various proportions while glycerin as a plasticizer. The patches were prepared by solvent casting technique and were subjected to various evaluation parameters like weight uniformity, content uniformity, thickness uniformity, swelling index, folding endurance, surface pH, and in vitro release studies. The Fourier transform infrared spectroscopic studies revealed that there was no interaction between drug and polymers. The viscosities of the polymeric solutions used for formulations were determined using Brookfield viscometer. The tensile strength of the patches was determined using Universal strength testing machine and found satisfactory.In vitro release studies were conducted for drug loaded patches in phosphate buffer solution, pH 6.6. The patches exhibited 48.73 to 102.21% drug release in 45 min. Data of in vitro release from the patches were fit to different equations and kinetic models to explain release profiles. In vitro release followed zero order kinetics. Release of terbutaline sulphate from the patches containing sodium alginate followed Higuchi’s model and mechanism was diffusion rate limited. In vivo studies in human volunteers showed 41.88% drug absorption in 30 min from formulation containing sodium alginate. Good correlation among in vitro release and in vivo absorption of terbutaline sulphate was observed (R2= 0.986)....
Curcumin (diferuloylmethane), a polyphenol, is an active principle of the perennial herb Curcuma longa (commonly known as turmeric). Curcumin possesses various medicinal properties. Despite curcumin’s multiple medicinal benefits, low oral bioavailability of curcumin continues to be highlighted as a major problem. Curcumin is safe and beneficial in several aliments was formulated into biodegradable microspheres with view to improve its oral bioavailability. Curcumin encapsulated microspheres prepared by coacervation-emulsification method were spherical in shape with particle size in range 0 to 30 µm and 72.97% entrapment at 58.72 loading. The curcumin encapsulated microspheres were able to withstand the International Conference on Harmonisation (ICH) accelerated stability test conditions for the studied duration of 3 months. XRD studies showed that the nature of pure drug curcumin remain unaffected till the completion of process of microspheres formation which was also supported by DSC results. In vitro release was predominantly by diffusion phenomenon and follows first order release pattern. The results clearly indicate the promise of microspheres for oral delivery of poorly bioavailable molecules like Curcumin....
The world of polymers is ever expanding and hence hunts for new effective polymers are always on. Abelmuschus esculentus a common vegetable used worldwide did raise eyebrows of many eminent people though not much was done in this regard. The aim was to investigate the excipient properties in its� mucilage. Binding, Disintegrating and bioadhesion were the properties studied. As the investigations proceeded the mucilage superseded our expectations and showed very good excipient properties. Coarse- fine ratio and hardness were the tools to evaluate binding efficacy whereas disintegration and dissolution studies were performed for disintegrant optimization. Modified Ranga Buri method and modified in vitro wash off test were carried out for bioadhesive analysis. All the results were statistically optimized by One Way ANOVA in Stat Plus 2007 software (Tukey HSD Test for Differences between Means) and conclusions drawn. 2%, 4% and 5% w/v concentrations showed very good disintegrating property, 3% w/v for binding action and above 6% w/v for bioadhesive action....
Microspheres constitute an important part of drug delivery system by virtue of there small size and efficient carrier characteristics. Microspheres in general have to the potential to be used for targeted and control released drug delivery: by coupling of mucoadhesive, oral, floating etc properties of microspheres. Novel drug delivery systems have several advantages over conventional multi dose therapy. Much research effort in developing novel drug delivery system has been focused on controlled release and sustained release dosage forms. Now considerable efforts are being made to deliver the drug in such a manner so as to get optimum benefits. There are various approaches in delivering a therapeutic substance to the target site in drug delivery systems. Microspheres are potential candidates for the protein drug delivery. These systems such as biodegradable microspheres are capable of delivering drugs over longer time periods than conventional formulations. Microspheres received much attention not only for prolonged release, but also for targeting of anticancer drugs to the tumor. The intent of the paper is to highlight method of preparation and novel drug delivery systems for microspheres....
In the present study nanoparticles of naproxen sodium were prepared for oral controlled release drug delivery using hydrophilic mucoadhesive polymer chitosan, showing appreciable controlled release and favorable physico-chemical properties required for easy oral administration. Incorporation efficiency of all formulations of nanoparticles was analyzed. In-vitro dissolution studies were carried out to study release of drug from nanoparticles in pH 7.4 phosphate buffer. The mechanisms influencing the drug release rate were adsorption, diffusion, hydrophilicity of drug and affinity of the drug for polymer. The release pattern shows anomalous behavior, as further confirmed by Higuchi plots. The formulations were characterized by Scanning Electron Microscopy for their size and morphological features. The Formulations were characterized by IR and TLC. From these studies it was confirmed that there is no interaction of the drug with the polymer. Mucoadhesion of the formulation to pig-intestinal mucosa was investigated...
Liposomes are prepared by thin film hydration (TFH) method; is very feasible and non-tedious techniques as compared to others. Budesonide and Formoterol liposomes prepared by TFH method and stored in amber colored vial, filled with nitrogen gas and stored in refrigerator till further use. Prepared liposomes were characterized by liposome size, zeta potential and percentage drug entrapment. Liposome size of budesonide and formetrol were 84.8 nm and 87.6 nm respectively. The zeta potential were also minimized i.e. -37 mV for budesonide and 5.21 mV for formetrol liposome. The process parameters like chloroform: methanol ratio, time for solvent evaporation, speed of rotation, volume of hydration, hydration time, number of sonication cycles and vacuum applied were optimized. The organic solvent system chloroform: methanol (4:1) used for preparation of budesonide liposome and chloroform: methanol (2:1) was used for preparation of formetrol liposome. For budesonide: increase in the lipid proportion relative to drug led to the increase in the drug entrapment from 28.51 % to 69.22 %. For formetrol: Increase in the lipid proportion relative to drug led to the increase in the drug entrapment from 22.456 % to 75.02 %. Prepared liposomes of selected drugs were separated by controlled centrifugation at low speed technique was selected for further development of liposomal DPIs....
Miniaturizing in chip technology, optics, micro mechanics, medicine, gene and biotechnology requires highly precise positioning techniques. The motivation for the new manipulation technology is the desire to enter the micro- and nanoworld not only by viewing but also acting, altering micro- and nanosized objects. A new era on medicine are expected to happen in the coming years. Due to the advances in the field of nanotechnology, nanodevice manufacturing has been growing gradually. From such achievements in nanotechnology, and recent results in biotechnology and genetics, the first operating biological nanorobots are expected to appear in the coming 5 years, and more complex diamondoid based nanorobots will become available in about 10 years. In terms of time it means a very near better future with significant improvements in medicine....
One of such system is transdermal Drug Delivery System. The design of effective transdermal drug delivery system has become an integral part of BIOPOLYMER of development of patches containing new medicines. The effects of various BIOPOLYMER on the Transdermal drug delivery system were evaluated. BIOPOLYMERS leads to advances in the field of research and science, and have paved the way for transdermal delivery system designs that have considerable flexibility and chemical penetration enhancers. An impressive amount of technical know-how has been gained in this area of research. This article summarizes the formulation aspects of transdermal drug delivery systems and emphasizes the physicochemical and mechanical properties of various Biopolymers being used in commercially available transdermal drug delivery systems. It is intended as a guide for the selection of Biopolymers for developing and evaluated transdermal delivery system....
Loading....