scholarly journals Development and Characterization of the Solvent-Assisted Active Loading Technology (SALT) for Liposomal Loading of Poorly Water-Soluble Compounds

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 465 ◽  
Author(s):  
Griffin Pauli ◽  
Wei-Lun Tang ◽  
Shyh-Dar Li

A large proportion of pharmaceutical compounds exhibit poor water solubility, impacting their delivery. These compounds can be passively encapsulated in the lipid bilayer of liposomes to improve their water solubility, but the loading capacity and stability are poor, leading to burst drug leakage. The solvent-assisted active loading technology (SALT) was developed to promote active loading of poorly soluble drugs in the liposomal core to improve the encapsulation efficiency and formulation stability. By adding a small volume (~5 vol%) of a water miscible solvent to the liposomal loading mixture, we achieved complete, rapid loading of a range of poorly soluble compounds and attained a high drug-to-lipid ratio with stable drug retention. This led to improvements in the circulation half-life, tolerability, and efficacy profiles. In this mini-review, we summarize our results from three studies demonstrating that SALT is a robust and versatile platform to improve active loading of poorly water-soluble compounds. We have validated SALT as a tool for improving drug solubility, liposomal loading efficiency and retention, stability, palatability, and pharmacokinetics (PK), while retaining the ability of the compounds to exert pharmacological effects.

2017 ◽  
Vol 5 (04) ◽  
pp. 17-23
Author(s):  
Katta Manogna ◽  
P. Nagaveni ◽  
K. Thyagaraju

Most of the newly invented chemical drug moieties are poorly water soluble. According to BCS classification, class II and IV drugs are considered as poorly water soluble. So enhancement of oral absorption and bioavailability of solid dosage forms remains a challenge to formulation scientists due to their solubility criteria. Therefore many techniques are being explored to enhance the solubility of poor soluble drugs. Solid dispersion is one of the most important method for enhance the solubility (dissolution rate) and hence oral bioavailability of poorly soluble drugs. In solid dispersion the particle size of drug is reduced or a crystalline pure drug is converted into amorphous form and hence the solubility is increased. Polymer incorporating in solid dispersion technology is usually hydrophilic in nature and also showing compatibility with the drug to enhance the drug solubility. This review mainly discus about solid dispersion, preparation methods, and finally characterization.


2020 ◽  
Vol 10 (1) ◽  
pp. 173-177 ◽  
Author(s):  
, Ikram ◽  
Kapil Kumar

Solid dispersion is a technique which is widely and successfully applied to improve the solubility, dissolution rates and consequently the bioavailability of poorly soluble drugs. Dispersion of one or more active ingredients (hydrophobic) is done with an inert carrier (hydrophilic) at solid-state prepared by fusion method, solvent, and melting solvent method. In this review article, we have focused on the methods of preparation, advantages, disadvantages and characterization of the solid dispersions. Keywords: Solid dispersion; dissolution; solubility.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Silvana Alfei ◽  
Gabriella Piatti ◽  
Debora Caviglia ◽  
Anna Maria Schito

The growing resistance of bacteria to current chemotherapy is a global concern that urgently requires new and effective antimicrobial agents, aimed at curing untreatable infection, reducing unacceptable healthcare costs and human mortality. Cationic polymers, that mimic antimicrobial cationic peptides, represent promising broad-spectrum agents, being less susceptible to develop resistance than low molecular weight antibiotics. We, thus, designed, and herein report, the synthesis and physicochemical characterization of a water-soluble cationic copolymer (P5), obtained by copolymerizing the laboratory-made monomer 4-ammoniumbuthylstyrene hydrochloride with di-methyl-acrylamide as uncharged diluent. The antibacterial activity of P5 was assessed against several multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species. Except for strains characterized by modifications of the membrane charge, most of the tested isolates were sensible to the new molecule. P5 showed remarkable antibacterial activity against several isolates of genera Enterococcus, Staphylococcus, Pseudomonas, Klebsiella, and against Escherichia coli, Acinetobacter baumannii and Stenotrophomonas maltophilia, displaying a minimum MIC value of 3.15 µM. In time-killing and turbidimetric studies, P5 displayed a rapid non-lytic bactericidal activity. Due to its water-solubility and wide bactericidal spectrum, P5 could represent a promising novel agent capable of overcoming severe infections sustained by bacteria resistant the presently available antibiotics.


2013 ◽  
Vol 49 (3) ◽  
pp. 571-578 ◽  
Author(s):  
Payal Hasmukhlal Patil ◽  
Veena Sailendra Belgamwar ◽  
Pratibha Ramratan Patil ◽  
Sanjay Javerilal Surana

The objective of the present work was to enhance the solubility and dissolution rate of the drug raloxifene HCl (RLX), which is poorly soluble in water. The solubility of RLX was observed to increase with increasing concentration of hydroxypropyl methylcellulose (HPMC E5 LV). The optimized ratio for preparing a solid dispersion (SD) of RLX with HPMC E5 LV using the microwave-induced fusion method was 1:5 w/w. Microwave energy was used to prepare SDs. HPMC E5 LV was used as a hydrophilic carrier to enhance the solubility and dissolution rate of RLX. After microwave treatment, the drug and hydrophilic polymer are fused together, and the drug is converted from the crystalline form into an amorphous form. This was confirmed through scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies. These results suggested that the microwave method is a simple and efficient method of preparing SDs. The solubility and dissolution rate of the SDs were increased significantly compared with pure RLX due to the surfactant and wetting properties of HPMC E5 LV and the formation of molecular dispersions of the drug in HPMC E5 LV. It was concluded that the solubility and dissolution rate of RLX are increased significantly when an SD of the drug is prepared using the microwave-induced fusion method.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1476
Author(s):  
Martina Ghezzi ◽  
Silvia Pescina ◽  
Andrea Delledonne ◽  
Ilaria Ferraboschi ◽  
Cristina Sissa ◽  
...  

Imiquimod (IMQ) is an immunostimulant drug approved for the topical treatment of actinic keratosis, external genital-perianal warts as well as superficial basal cell carcinoma that is used off-label for the treatment of different forms of skin cancers, including some malignant melanocytic proliferations such as lentigo maligna, atypical nevi and other in situ melanoma-related diseases. Imiquimod skin delivery has proven to be a real challenge due to its very low water-solubility and reduced skin penetration capacity. The aim of the work was to improve the drug solubility and skin retention using micelles of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), a water-soluble derivative of vitamin E, co-encapsulating various lipophilic compounds with the potential ability to improve imiquimod affinity for the micellar core, and thus its loading into the nanocarrier. The formulations were characterized in terms of particle size, zeta potential and stability over time and micelles performance on the skin was evaluated through the quantification of imiquimod retention in the skin layers and the visualization of a micelle-loaded fluorescent dye by two-photon microscopy. The results showed that imiquimod solubility strictly depends on the nature and concentration of the co-encapsulated compounds. The micellar formulation based on TPGS and oleic acid was identified as the most interesting in terms of both drug solubility (which was increased from few µg/mL to 1154.01 ± 112.78 µg/mL) and micellar stability (which was evaluated up to 6 months from micelles preparation). The delivery efficiency after the application of this formulation alone or incorporated in hydrogels showed to be 42- and 25-folds higher than the one of the commercial creams.


Author(s):  
Samer K. Ali ◽  
Eman B. H. Al-Khedairy

            Atorvastatin (ATR) is poorly soluble anti-hyperlipidemic drug; it belongs to the class II group according to the biopharmaceutical classification system (BCS) with low bioavailability due to its low solubility. Solid dispersions adsorbate is an effective technique for enhancing the solubility and dissolution of poorly soluble drugs.           The present study aims to enhance the solubility and dissolution rate of ATR using solid dispersion adsorption technique in comparison with ordinary solid dispersion. polyethylene glycol 4000 (PEG 4000), polyethylene glycol 6000 (PEG 6000), Poloxamer188 and Poloxamer 407were used as hydrophilic carriers and Aerosil 200, Aerosil 300 and magnesium aluminium silicate (MAS) as adsorbents.            All solid dispersion adsorbate (SDA) formulas  were prepared in ratios of 1:1:1  (drug: carrier: adsorbent) and evaluated for their water solubility, percentage yield, drug content,  , dissolution, crystal structure using  X-ray powder diffraction (XRD) and Differential Scanning Calorimetry (DSC)  studies and Fourier Transform Infrared Spectroscopy (FTIR) for determination the drug-carrier- adsorbate interaction.                The prepared (SDA) showed significant improvement of drug solubility in all prepared formula. Best result was obtained with formula SDA12(ATR :Poloxamer407 : MAS 1:1:1) that showed 8.07 and 5.38  fold increase in solubility compared to  solubility of pure ATR and  solid dispersion(SD4) (Atorvastatin: Poloxamer 407 1:1) respectively due to increased wettability and reduced crystallinity of the drug which leads to improve drug solubility  and  dissolution .


Author(s):  
Sabitri Bindhani ◽  
Snehamayee Mohapatra

 Solid dispersion (SD) has been a major advanced technology in overcoming dissolution and bioavailability problem of poorly soluble compounds. Formulation of SD in water-soluble carrier has becoming more researched over the past four decades for solubility and relative bioavailability enhancement. By reduction of the size of the drug particle to the minimum level which will enhance drug wettability and ultimately bioavailability will be definitely improved. This review article elaborates recent advanced technology and characterization of SDs and also discusses the problems and their solution for the development of better formulations.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qingyun Zeng ◽  
Liquan Ou ◽  
Guowei Zhao ◽  
Ping Cai ◽  
Zhenggen Liao ◽  
...  

Solid dispersion (SD) is the effective approach to improve the dissolution rate and bioavailability of class II drugs with low water solubility and high tissue permeability in the Biopharmaceutics Classification System. This study investigated the effects of polyethylene glycol (PEG) molecular weight in carrier material PEG palmitate on the properties of andrographolide (AG)-SD. We prepared SDs containing the poorly water-soluble drug AG by the freeze-drying method. The SDs were manufactured from two different polymers, PEG4000 palmitate and PEG8000 palmitate. The physicochemical properties of the AG-SDs were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, dissolution testing, and so on. We found that AG-PEG4000 palmitate-SD and AG-PEG8000 palmitate-SD were similar in the surface morphology, specific surface area, and pore volume. Compared with the AG-PEG4000 palmitate-SD, the intermolecular interaction between PEG8000 palmitate and AG was stronger, and the thermal stability of AG-PEG8000 palmitate-SD was better. In the meanwhile, the AG relative crystallinity was lower and the AG dissolution rate was faster in AG-PEG8000 palmitate-SD. The results demonstrate that the increasing PEG molecular weight in the PEG palmitate can improve the compatibility between the poorly water-soluble drug and carrier material, which is beneficial to improve the SD thermal stability and increases the dissolution rate of poorly water-soluble drug in the SD.


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