Effect of sugars on freeze-thaw and lyophilization of liposomes

Vemuri, Sriram; Yu, Cheng-Der; Degroot, Jennifer S.; Wangsatornthnakun, Vuthichai; Venkataram, Seresh

doi:10.3109/03639049109043831

Cited by 22 publications

(7 citation statements)

References 8 publications

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“…The particle size and PI in the reconstituted solution are close to those before freeze‐drying. The saccharides were often used as cryoprotectant in the freeze‐drying of liposomes and solid lipid nanoparticles by decreasing the osmotic activity of water crystallization and favor the glassy state of the frozen sample 25. However, the saccharides cannot act as steric stabilizer and form a coating layer on the surface of particles to prevent the micelles from aggregation.…”

Section: Resultsmentioning

confidence: 99%

“…The saccharides were often used as cryoprotectant in the freeze-drying of liposomes and solid lipid nanoparticles by decreasing the osmotic activity of water crystallization and favor the glassy state of the frozen sample. 25 However, the saccharides cannot act as steric stabilizer and form a coating layer on the surface of particles to prevent the micelles from aggregation. The particle size and PI in the reconstituted solution determined by DLS were distinctly increased because of the formation of micron-sized aggregates.…”

Section: Effects Of Lyoprotcetants On Micelle Size During Freeze-dryingmentioning

confidence: 99%

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Amphotericin B‐loaded poly(ethylene glycol)–poly(lactide) micelles: Preparation, freeze‐drying, and in vitro release

Zhuo

Yang

et al. 2007

J Biomedical Materials Res

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Polymeric micelles prepared from a series of poly(ethylene glycol)-poly(lactide) (PEG-PLA) diblock copolymers with various PLA chain lengths were designed as drug carriers for water insoluble drug amphotericin B (AmB). Physicochemical properties of AmB-loaded micelles were evaluated. Micelles were freeze-dried to obtain long-time stable formulations. The redispersibility of the freeze-dried samples was poor when the weight ratio of PLA block was bigger than the PEG block of the copolymer. Various types of lyoprotectants including saccharides and PEGs with different molecular weight were tested to improve the redispersion performance of the freeze-dried samples. PEG was proved to be more effective than saccharides on stabilizing the micelles during lyophilization when the weight ratio of PLA block was bigger than PEG block. The sustained release in vitro of AmB was evidenced. About 80% of AmB was released in 80 h. The in vitro release behavior could be best described by the first-order equation. The release rate was reduced as enhancing PLA chain length due to the stronger interaction between poorly water-soluble AmB and longer hydrophobic chain length of PLA.

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Section: Resultsmentioning

confidence: 99%

Section: Effects Of Lyoprotcetants On Micelle Size During Freeze-dryingmentioning

confidence: 99%

Amphotericin B‐loaded poly(ethylene glycol)–poly(lactide) micelles: Preparation, freeze‐drying, and in vitro release

Zhuo

Yang

et al. 2007

J Biomedical Materials Res

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“…To maintain the same particle size distribution after freeze-drying-rehydration cycle, a cryoprotectant needs to be added. Various sugars were investigated for their ability to protect liposomes against fusion and leakage during lyophilization processes (Venuri et al, 1991). This protective ability can extend to both prevention of vesicle fusion and retention of encapsulated compound within the liposome (Madden and Boman, 1999).…”

Section: Freeze-drying Of Fluconazole Liposomesmentioning

confidence: 99%

“…Some liposomal products in the market or in clinical trials are provided as a lyophilized powder (Sharma and Sharma, 1997). The leakage problem is one of the limiting factors in the commercial development of liposome products (Venuri et al, 1991). A variety of sugars, including sucrose, glucose, fructose, maltose, arabinose and trehalose, have been shown to act as protectants during dehydration/rehydration of liposomes (Crowe et al, 1985).…”

Section: Introductionmentioning

confidence: 99%

Effect of formulation design and freeze-drying on properties of fluconazole multilamellar liposomes

El-Nesr

Yahiya

El‐Gazayerly

2010

Saudi Pharmaceutical Journal

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Fluconazole-entrapped multilamellar liposomes were prepared using the thin-film hydration method. The effects of cholesterol molar ratio, charge-inducing agents, and α-tocopherol acetate on encapsulation efficiency values and in vitro drug release of multilamellar liposomes were studied. Freeze-dried liposomal products were prepared with or without cryoprotectants. Results showed that incorporation of stearylamine resulted in an increased entrapment of fluconazole, whereas incorporation of dicetyl phosphate decreased the drug entrapment efficiency. The incorporation of α-tocopherol acetate into fluconazole multilamellar liposomes resulted in the increase of entrapment efficiency of fluconazole liposomes. In vitro release studies revealed that incorporation of cholesterol into multilamellar liposomal formulations decreased drug permeability from formulations. Positively charged fluconazole multilamellar liposomes gave rise to a slow release rate compared to neutral liposomes whereas negatively charged fluconazole liposomes showed a rapid release rate. Physical stability studies showed that lyophilized cake of liposomes without cryoprotectants was compact and difficult to reconstitute compared to fluffy easily reconstituted cakes upon using cryoprotectants. Fluconazole retained in freeze-dried liposomes without cryoprotectants was 63.452% compared to 91.877% using three grams of trehalose as a cryoprotectant per gram lipid in positively charged multilamellar liposomes. Physical stability studies showed superior potentials of the lyophilized product after reconstitution in comparison with those of a solution product.

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“…Indeed, liposomes have been successfully lyophilized previously and were shown to preserve their encapsulated content best when freeze-dried in solutions containing saccharides 11-16. The short and long-term storage of lyophilized liposomes was also investigated 17-19.…”

Section: Introductionmentioning

confidence: 99%

Investigating Lyophilization of Lipid Nanocapsules with Fluorescence Correlation Spectroscopy

2010

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This paper describes characterization of lyophilized lipid nanocapsules loaded with Alexa 488 by fluorescence correlation spectroscopy (FCS). Fluorimetry analysis of nanocapsules containing selfquenching concentrations of 5-(and-6)-carboxyfluorescein was performed to establish a point of reference for FCS. FCS results complemented the results obtained by fluorimetry for a bulk nanocapsule solution and provided additional information about the size and dye retention by individual nanocapsules. Using this method, we determined that nanocapsules composed of the thiolfunctionalized lipids showed the best dye retention and the most consistent results. Dye retention, size, and photolysis efficiency of these thiol-functionalized nanocapsules doped with a far-red photosensitizer did not change substantially upon lyophilization and storage at −20 °C for up to two months, making lyophilization a suitable method for the long-term storage of nanocapsules with the appropriate lipid composition.

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Effect of sugars on freeze-thaw and lyophilization of liposomes

Cited by 22 publications

References 8 publications

Amphotericin B‐loaded poly(ethylene glycol)–poly(lactide) micelles: Preparation, freeze‐drying, and in vitro release

Amphotericin B‐loaded poly(ethylene glycol)–poly(lactide) micelles: Preparation, freeze‐drying, and in vitro release

Effect of formulation design and freeze-drying on properties of fluconazole multilamellar liposomes

Investigating Lyophilization of Lipid Nanocapsules with Fluorescence Correlation Spectroscopy

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