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Bioinspired Nano-Formulations
Published in Yasser Shahzad, Syed A.A. Rizvi, Abid Mehmood Yousaf, Talib Hussain, Drug Delivery Using Nanomaterials, 2022
Jahanzeb Mudassir, Muhammad Sohail Arshad
The synthetic polymeric materials used to prepare bioinspired nano-formulations generally contribute in improving stability and regulate the drug release at cellular, tissue, and organ levels. Other advantages include enhancing the drug permeability, improving solubility, as well as bioavailability. Among the carboxylic acid group containing materials, which are used for the preparation of bioinspired nano-formulations, the poloxamers and their derivatives are widely used as inert biomimetic polymers (Ranjha et al. 2010; Ranjha, Mudassir, and Majeed 2011; Ranjha, Mudassir, and Zubair 2011). These are block copolymer composed of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO). Poloxamers show favorable characteristics, e.g., preparing self-assembled nano-formulations like polymeric micelles of water in soluble drug (Bangde et al. 2017, Harwansh et al. 2019; Merkle 2015). PLGA is biodegradable and biocompatible polymeric material and is approved for incorporation with high molecular weight proteins and peptide drugs for parenteral administration. PLGA act by triggering biological response and is widely used for drug delivery and site specific targeting. Poly(γ-glutamic Acid) (PGA) is water soluble and biodegradable polymeric material and is widely used to develop advanced pharmaceutical bioinspired nano-formulations. PGA could be conjugated with variety of materials. Few of PGA-based conjugated drugs are in clinical trial phase (Harwansh et al. 2019; Merkle 2015).
Impact of Physicochemical Properties on Dendrimer Pharmacokinetics and Biodistribution
Published in Delphine Felder-Flesch, Dendrimers in Nanomedicine, 2016
Orlagh Feeney, Suzanne M. Caliph, Christopher J. H. Porter, Lisa M. Kaminskas
Oral drug administration is simple, convenient and in general, offers better compliance and outcomes, at least for small molecule drugs. In recent times, however, oral drug delivery has become increasingly challenging with the emergence of new generations of highly potent, but poorly water soluble and poorly bioavailable compounds. Thus, appropriate formulation of these compounds with drug carriers may enhance oral bioavailability. Dendrimers have been suggested to enhance oral bioavailability by promoting drug solublization in the intestinal lumen, inhibit drug-efflux transporter interactions, prevent intestinal elimination of drugs and enhance drug permeability by disrupting epithelial tight junctions in the intestines. The use of dendrimers for oral drug delivery, however, is challenging as a result of their macromolecular size and hydrophilicity that ultimately limits intestinal permeability, together with poorly controllable drug release profiles in the gastrointestinal tract. Nevertheless, there have been some, despite few, important examples of enhanced in vivo bioavailability of drugs when associated with dendrimers. As an example, the bioavailability of doxorubicin has been shown to be enhanced 300-fold when delivered as a complex with an amine-terminated G3 PAMAM dendrimer, compared to delivery of the free drug.36 The mechanism by which this increase in bioavailability occurred was not clear but may have been due to reduced interaction of doxorubicin with intestinal efflux transporters, increased drug solubility or altered mechanisms of drug transport across the intestine. More recently, both cationic and anionic G4 PAMAM dendrimers were shown to improve the oral bioavailability of camptothecin in mice by 2- to 3-fold.68
Multi-Cyclodextrin Supramolecular Encapsulation Entities for Multifaceted Topical Drug Delivery Applications
Published in Munmaya K. Mishra, Applications of Encapsulation and Controlled Release, 2019
P. D. Kondiah, Yahya E. Choonara, Zikhona Hayiyana, Pariksha J. Kondiah, Thashree Marimuthu, Lisa C. du Toit, Pradeep Kumar, Viness Pillay
Topical delivery systems are one of the most popular applications of controlled, encapsulated drug delivery platforms. This is due to the ease of administration and the direct application, which translates to site specificity, enhanced therapeutic effectiveness, and elimination of systemic side effects, such as hepatotoxicity, through bypassing the hepatic metabolic processes (Park et al. 2017). Topical formulations have to be compatible with the body surface at the intended area of administration, since interactions of the formulation with the surface will affect the pharmacokinetic properties of bioactives. This includes permeation across the biological membranes, drug release behavior, solubility, absorption, and the overall pharmacological activity (Choudhury et al. 2017). Various drug delivery systems are constantly being developed to improve the pharmacokinetics of topically delivered drug molecules (Choudhury et al 2017). Recent researches have revealed the capability of cyclodextrins (CDs) in enhancing drug permeability, solubility, and bioavailability without severely altering the biological barrier as well as the drug functionality (Xu et al. 2018). CDs form one of the most versatile technologies that have the capability to encapsulate a wide range of drug molecules for a variety of applications (Sherje et al. 2017). This chapter aims to highlight the application of CDs in topical drug delivery and how their benefits can be modified through the formulation of multi-cyclodextrin entities. The topical administration routes discussed in this chapter are divided into three categories: surface of tissues (ocular, oral cavity, and tooth surface routes), skin (dermal route), and mucous membranes (buccal, sublingual, and nasal). The current applications of CDs in these routes are elaborated and the substantial benefit of multi-cyclodextrin entities proposed.
Franz diffusion cell and its implication in skin permeation studies
Published in Journal of Dispersion Science and Technology, 2023
Mohit Kumar, Ankita Sharma, Syed Mahmood, Anil Thakur, Mohd Aamir Mirza, Amit Bhatia
According to the EMA, in vitro permeation tests assess drug permeability through skin layers. Furthermore, the EMA does not necessarily anticipate finding a link between permeation data and in vivo permeation. The use of human skin or skin from animals such as a pig, rodent, guinea pig, or artificial/synthetic membrane is permissible for the in vitro permeation investigation, Until the model is justified. The same membrane or skin should be utilized to compare a generic product. To reduce skin variability, the EMA advises typically six or more replicates from at least two or more donors in the research. When biological skin is utilized, the species and body part where the skin was acquired must be indicated. The storage conditions and skin thickness should be described and justified. At the start of the trial, the skin integrity should be evaluated and justified. Transepithelial electrical resistance (TEER), trans-epidermal water loss (TEWL), and tritiated water permeation should all be used to test the skin’s integrity. The Franz diffusion cell accepts surface areas ranging from 0.5 to 2.0 cm2. Two Franz cells are used in permeation studies: commercially made Franz cells (expensive and with the least variable) and hand-blown Franz cells (cheap and with variability dependent on the technician’s expertise). For water-soluble medications, the receptor media in the permeation research should be an aqueous buffer, but for weakly water-soluble pharmaceuticals, hydroalcoholic media or aqueous buffers containing solubility enhancers such as protein solutions are utilized. The receptor solution employed in the investigation should not affect the skin or membrane integrity. As a result, the use of surfactants in receptor media is restricted because of the risk of compromising skin integrity.[154] It is critical to maintain the sink condition in the receptor chamber so that the drug concentration does not exceed 10-30% of the receptor solution’s maximal solubility. Five or more sampling points, appropriately scheduled to demonstrate permeation, should be used. After the permeation research, the samples can be evaluated with an approved analytical method, such as high-performance liquid chromatography (HPLC) or liquid chromatography-mass spectrometry (LC-MS).[155]