Method to Investigate the Distribution of Water-Soluble Drug-Delivery Systems in Fresh Frozen Tissues Using Imaging Mass Cytometry

Author(s):  
Nicole Strittmatter ◽  
Richard M. England ◽  
Alan M. Race ◽  
Daniel Sutton ◽  
Jennifer I. Moss ◽  
...  
2012 ◽  
Vol 62 (2) ◽  
pp. 237-250 ◽  
Author(s):  
Anurag Verma ◽  
Ashok Bansal ◽  
Amitava Ghosh ◽  
Jayanta Pandit

Low molecular mass chitosan as carrier for a hydrodynamically balanced system for sustained delivery of ciprofloxacin hydrochloride Chitosan has become a focus of major interest in recent years due to its excellent biocompatibility, biodegradability and non-toxicity. Although this material has already been extensively investigated in the design of different types of drug delivery systems, it is still little explored for stomach specific drug delivery systems. The objective of the present investigation was to explore the potential of low molecular mass chitosan (LMCH) as carrier for a hydrodynamically balanced system (HBS) for sustained delivery of water soluble drug ciprofloxacin hydrochloride (CP). Various formulations were prepared by physical blending of drug and polymer(s) in varying ratios followed by encapsulation into hard gelatin capsules. All the formulations remained buoyant in 0.1 mol L-1 HCl (pH 1.2) throughout the experiment. Effect of addition of xanthan gum (XG) or ethyl cellulose (EC) on drug release was also investigated. Zero order drug release was obtained from the formulations containing LMCH alone or in combination with XG, and in one instance also with EC. Our results suggest that LMCH alone or in combination with XG is an excellent material for stomach specific sustained delivery of CP from hydrodynamically balanced single unit capsules.


2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Shweta Gupta ◽  
Rajesh Kesarla ◽  
Abdelwahab Omri

Poorly water-soluble drug candidates are becoming more prevalent. It has been estimated that approximately 60–70% of the drug molecules are insufficiently soluble in aqueous media and/or have very low permeability to allow for their adequate and reproducible absorption from the gastrointestinal tract (GIT) following oral administration. Formulation scientists have to adopt various strategies to enhance their absorption. Lipidic formulations are found to be a promising approach to combat the challenges. In this review article, potential advantages and drawbacks of various conventional techniques and the newer approaches specifically the self-emulsifying systems are discussed. Various components of the self-emulsifying systems and their selection criteria are critically reviewed. The attempts of various scientists to transform the liquid self-emulsifying drug delivery systems (SEDDS) to solid-SEDDS by adsorption, spray drying, lyophilization, melt granulation, extrusion, and so forth to formulate various dosage forms like self emulsifying capsules, tablets, controlled release pellets, beads, microspheres, nanoparticles, suppositories, implants, and so forth have also been included. Formulation of SEDDS is a potential strategy to deliver new drug molecules with enhanced bioavailability mostly exhibiting poor aqueous solubility. The self-emulsifying system offers various advantages over other drug delivery systems having potential to solve various problems associated with drugs of all the classes of biopharmaceutical classification system (BCS).


Author(s):  
Navneet Sharma ◽  
Sabna Kotta ◽  
Mohd Aleem ◽  
Shubham Singh ◽  
Rakesh Kumar Sharma

In the last decade, there has been a mounting concern in lipid-based formulations to deliver water-soluble drugs. Lipid-based drug delivery systems are one of the budding and promising technologies designed to tackle the poor bioavailability problems. This chapter stresses the different mechanisms of lipophilic drug absorption along with its advantages and limitations. It points out the different mechanisms of how lipid-based excipients and the different formulations interact with the absorption process. This review provides a comprehensive summary about the lipid formulation classification scheme (LFCS), a guide for the selection of appropriate formulation and commonly used excipients for lipid-based formulations, along with the important factors to be considered in formulation design and excipient selection. This review also focuses on the formulation of solid lipid-based formulations, important evaluation aspects, and commercial formulations available for the purpose.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 495 ◽  
Author(s):  
Hakkarainen ◽  
Kõrkjas ◽  
Laidmäe ◽  
Lust ◽  
Semjonov ◽  
...  

We investigated nozzleless ultrasound-enhanced electrospinning (USES) as means to generate nanofibrous drug delivery systems (DDSs) for pharmaceutical and biomedical applications. Traditional electrospinning (TES) equipped with a conventional spinneret was used as a reference method. High-molecular polyethylene oxide (PEO) and chitosan were used as carrier polymers and theophylline anhydrate as a water-soluble model drug. The nanofibers were electrospun with the diluted mixture (7:3) of aqueous acetic acid (90% v/v) and formic acid solution (90% v/v) (with a total solid content of 3% w/v). The fiber diameter and morphology of the nanofibrous DDSs were modulated by varying ultrasonic parameters in the USES process (i.e., frequency, pulse repetition frequency and cycles per pulse). We found that the USES technology produced nanofibers with higher fiber diameter (402 ± 127 nm) than TES (77 ± 21 nm). An increase of a burst count in USES increased the fiber diameter (555 ± 265 nm) and the variation in fiber size. The slight-to-moderate changes in a solid state (crystallinity) were detected when compared the nanofibers generated by TES and USES. In conclusion, USES provides a promising alternative for aqueous-based fabrication of nanofibrous DDSs for pharmaceutical and biomedical applications.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 267 ◽  
Author(s):  
Tao Yi ◽  
Jifen Zhang

Self-microemulsifying drug delivery systems (SMEDDS) offer potential for improving the oral bioavailability of poorly water-soluble drugs. However, their susceptibilities during long term storage and in vivo precipitation issues limit their successful commercial application. To overcome these limitations, SMEDDS can be solidified with solid carriers, thus producing solid self-microemulsifying drug delivery systems (S-SMEDDS). In this study, effects of various hydrophilic carriers on structural transitions and in vitro properties of S-SMEDDS were investigated in order to set up in vitro methods for screening out appropriate carriers for S-SMEDDS. Liquid SMEDDS was prepared and characterized using nimodipine as a model drug. The effects of various hydrophilic carriers on internal microstructure and solubilization of SMEDDS were investigated by conductivity measurement and in vitro dispersion test. The results showed that hydrophilic carriers including dextran 40, maltodextrin and PVP K30 seemed to delay the percolation transition of SMEDDS, allowing it to maintain a microstructure that was more conducive to drug dissolution, thus significantly increasing the solubilization of nimodipine in the self-microemulsifying system and decreasing drug precipitation when dispersed in simulated gastric fluid. S-SMEDDS of nimodipine were prepared by using spray drying with hydrophilic carriers. The effects of various hydrophilic carriers on in vitro properties of S-SMEDDS were investigated by using SEM, DSC, PXRD and in vitro dissolution. The results showed that properties of hydrophilic carriers, especially relative molecular mass of carriers, had obvious influences on surface morphologies of S-SMEDDS, reconstitution of microemulsion and physical state of nimodipine in S-SMEDDS. Considering that in vitro properties of S-SMEDDS are closely related to their pharmacokinetic properties in vivo, the simple and economical in vitro evaluation methods established in this paper can be used to screen solid carriers of S-SMEDDS well.


ChemInform ◽  
2016 ◽  
Vol 47 (32) ◽  
Author(s):  
Xuan Wu ◽  
Lei Gao ◽  
Xiao-Yu Hu ◽  
Leyong Wang

1999 ◽  
Vol 40 (9) ◽  
pp. 1743-1746 ◽  
Author(s):  
Lance J. Twyman ◽  
Anthony E. Beezer ◽  
R. Esfand ◽  
Martin J. Hardy ◽  
John C. Mitchell

2013 ◽  
Vol 63 (4) ◽  
pp. 427-445 ◽  
Author(s):  
Katja Čerpnjak ◽  
Alenka Zvonar ◽  
Mirjana Gašperlin ◽  
Franc Vrečer

Abstract Low oral bioavailability as a consequence of low water solubility of drugs is a growing challenge to the development of new pharmaceutical products. One of the most popular approaches of oral bioavailability and solubility enhancement is the utilization of lipid-based drug delivery systems. Their use in product development is growing due to the versatility of pharmaceutical lipid excipients and drug formulations, and their compatibility with liquid, semi-solid, and solid dosage forms. Lipid formulations, such as self-emulsifying (SEDDS), self-microemulsifying SMEDDS) and self- -nanoemulsifying drug delivery systems (SNEDDS) were explored in many studies as an efficient approach for improving the bioavailability and dissolution rate of poorly water-soluble drugs. One of the greatest advantages of incorporating poorly soluble drugs into such formulations is their spontaneous emulsification and formation of an emulsion, microemulsion or nanoemulsion in aqueous media. This review article focuses on the following topics. First, it presents a classification overview of lipid-based drug delivery systems and mechanisms involved in improving the solubility and bioavailability of poorly water-soluble drugs. Second, the article reviews components of lipid-based drug delivery systems for oral use with their characteristics. Third, it brings a detailed description of SEDDS, SMEDDS and SNEDDS, which are very often misused in literature, with special emphasis on the comparison between microemulsions and nanoemulsions.


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