82 research outputs found
Formulation of cell-based medicinal products: a question of life or death?
The formulation of cell-based medicinal products (CBMPs) poses major challenges because of their complexity, heterogeneity, interaction with their environment (e.g., the formulation buffer, interfaces), and susceptibility to degradation. These challenges can be quality, safety, and efficacy related. In this commentary we discuss the current status in formulation strategies of off-the-shelf and non-off-the-shelf (patient-specific) CBMPs and highlight advantages and disadvantages of each strategy. Analytical tools for the characterization and stability assessment of CBMP formulations are addressed as well. Finally, we discuss unmet needs and make some recommendations regarding the formulation of CBMPs. (C) 2020 American Pharmacists Association?. Published by Elsevier Inc. All rights reserved.Personalised Therapeutic
Ongoing challenges to develop high concentration monoclonal antibody-based formulations for subcutaneous administration: Quo Vadis?
Although many subcutaneously (s.c.) delivered, high-concentration antibody formulations (HCAF) have received regulatory approval and are widely used commercially, formulation scientists are still presented with many ongoing challenges during HCAF development with new mAb and mAb-based candidates. Depending on the specific physicochemical and biological properties of a particular mAb-based molecule, such challenges vary from pharmaceutical attributes e.g., stability, viscosity, manufacturability, to clinical performance e.g., bioavailability, immunogenicity, and finally to patient experience e.g., preference for s.c. vs. intravenous delivery and/or preferred interactions with health-care professionals. This commentary focuses on one key formulation obstacle encountered during HCAF development: how to maximize the dose of the drug? We examine methodologies for increasing the protein concentration, increasing the volume delivered, or combining both approaches together. We discuss commonly encountered hurdles, i.e., physical protein instability and solution volume limitations, and we provide recommendations to formulation scientists to facilitate their development of s.c. administered HCAF with new mAb-based product candidates.Drug Delivery Technolog
Labelled StealthR liposomes in experimental infection : an alternative to leukocyte scintigraphy?
Item does not contain fulltex
Sterically stabilized liposomes labeled with Indium-111 to image focal infection
Contains fulltext :
21192___.pdf (publisher's version ) (Open Access
Comparison of breast-conserving therapy with mastectomy for treatment of early breast cancer in community hospitals
Although the results of clinical trials support breast-conserving therapy as a replacement for mastectomy in early breast cancer, the question remains,whether these results apply in routine clinical practice. In the present analysis the breast cancer-specific survival and recurrence-free survival of 464 consecutive patients with breast tumours ā¤ 3 cm across undergoing breast-conserving therapy were compared with a group of 459 patients with similar extent of disease and period of diagnosis undergoing mastectomy. All patients were treated in community hospitals in the south-eastern Netherlands. Median follow-up of both treatment groups was 6.2 years. After adjustment for the prognostic effects of age, tumour size, axillary nodal status and adjuvant systemic therapy, neither breast cancer-specific survival nor recurrence-free survival differed significantly between the breast-conserving therapy group and the mastectomy group. This finding indicates that in routine clinical practice breast-conserving therapy may be as effective as mastectomy
Detecting infection and inflammation with technetium-99m-labeled stealth liposomes
Contains fulltext :
4843.pdf (publisher's version ) (Open Access
Critical factors for liposome-incorporated tumour-associated antigens to induce protective tumour immunity to SL2 lymphoma cells in mice
Physical
and
immunogenic
properties
of
re-
constituted
membranes
designed
for
the
presentation
of
tumour-associated
antigens
(TAA)
to
the
immune
system
are
described.
Proteins
and
lipids
of
crude
membranes
of
SL2
routine
lymphosarcoma
cells
were
partially
solubi-
lized
with
octylglucoside.
Reconstituted
membranes,
con-
sisting
mainly
of
unilamellar
vesicles
with
a
diameter
of
0.03-0.15
gm,
were
formed
by
detergent
removal
and
were
purified
by
floatation
in
a
discontinuous
sucrose
gra-
dient
to
remove
non-lipid-bound
protein.
Subcutaneous
immunization
of
syngeneic
mice
with
reconstituted
mem-
branes
or
with
purified
reconstituted
membranes
induced
protection
against
an
intraperitoneal
challenge
with
103
viable
SL2
cells.
Reconstituted
membranes
were
more
im-
munogenic
than
crude
membranes
in
immunoprotection
experiments
when
compared
on
the
basis
of
protein
dose.
Detergent
removal
was
required
to
obtain
an
immunogenic
presentation
form
of
SL2
membrane
antigens
and
to
avoid
toxicity
associated
with
the
detergent.
Reconstitution
of
SL2
membranes
in
the
presence
of
exogenous
phos-
pholipid
slightly
increased
the
fraction
of
protein
that
as-
sociated
with
the
reconstituted
membranes.
However,
the
immunogenicity
of
the
solubilized
membrane
TAA
was
not
significantly
affected
by
the
presence
of
exogenous
phospholipid.
The
reconstitution
procedure
described
may
be
useful
in
identifying
membrane
factors
required
for
the
induction
of
immune
responses
against
TAA.
The
versatil-
ity
of
the
system
may
be
employed
to
develop
safe
alterna-
tives
for
whole-cell
vaccines
Stability of doxorubicin-liposomes on storage : as an aqueous dispersion, frozen or freeze-dried
Shelf-life of doxorubicin (DXR) containing negatively charged liposomes was studied under various conditions. The following parameters were monitored: DXR-latency, stability against aggregation or fusion, and chemical stability of bilayer components and associated DXR. An ion exchange resin was used to remove free DXR from liposome-associated DXR. As an alternative for storing aqueous dispersions, the liposomes were frozen and freeze-dried. Variables under investigation were: type of cryoprotectant (saccharides, polyvinylpyrrolidone and mannitol), particle size (about 0.1, 0.25 and 0.65 Ī¼m), physical state of the bilayer (āgelā- or āfluidā-like, inclusion of Ī±-tocopherolacetate). A comparison was made between the behaviour of a bilayer interacting compound (DXR) and a non-interacting compound (carboxyfluorescein, CF).
When stored as aqueous dispersions extruded multilamellar structures (0.25 Ī¼m) showed lower DXR leakage rates than sonicated vesicles (0.1 Ī¼m). In the presence of various saccharides freezing and freeze-drying resulted in similar DXR latencies on thawing or rehydration; they provided adequate protection against aggregation or fusion. Other cryoprotectants failed. Latency of a bilayer-interacting drug like DXR, was hardly sensitive to variation of the bilayer structure; in contrast to this observation, latency of CF strongly depended on the bilayer composition. Under the experimental conditions no effects of ageing could be observed in terms of changing leakage profiles, aggregation behaviour or chemical decomposition of DXR
In vitro release studies on drugs suspended in non-polar media II. The release of paracetamol and chloramphenicol from suspensions in liquid paraffin
The release of paracetamol and chloramphenicol (water solubility 13 and 3.6 mg Ā· gā1, respectively), suspended in liquid paraffin, to an underlying aqueous layer was investigated as a function of particle size (10ā60 Ī¼m), concentration (0.5ā6% m/m) and the presence of additives (DOSS-Na: di-(2-ethylhexyl) sodium sulphosuccinate and/or water) in the liquid paraffin. A hypothesis was formulated predicting the release to be independent of particle size, concentration and degree of coverage of the interface by particles, if the mass flow of the interface would exceed the dissolution rate of the particles at the interface. This limiting rate would approximate the intrinsic dissolution rate. The experimental results showed that for low concentrations the release was determined by the settling mass flow. With more concentrated suspensions the release was dissolution controlled and in general a good agreement with the proposed hypothesis was found.
Addition of water (0.01 or 0.05% m/m) to the suspensions increased the degree of agglomeration and reduced the degree of interfacial coverage, but did not change the release rate. The presence of 0.2% m/m DOSS-Na in the paracetamol suspensions did not influence the rate either, but in combination with water (0.01 or 0.05% m/m) an increase was observed; the particles did not stay at the interface during dissolution, but they fell through it as such. With chloramphenicol this happened already in the presence of 0.2% m/m DOSS-Na. Water addition enhanced this effect dramatically
In vitro release studies on drugs suspended in non-polar media I. Release of sodium chloride from suspensions in liquid paraffin
The release of a readily water-soluble substance (sodium chloride) from a liquid paraffin phase to an underlying water phase was investigated as a function of particle size (10ā50 Ī¼m) and concentration (up to 10% m/m). Transport of the suspended particles to the interface by sedimentation was the rate limiting step. The release rate increased with primary particle size and concentration. The small particles showed a more pronounced concentration dependence than the large ones. During settling, agglomerates were formed. But, mild shear rates kept the primary particles in the deglomerated state. Low concentrations of DOSS-Na (di(2-ethylhexyl) sodium sulphosuccinate) up to 0.2% m/m in liquid paraffin reduced the degree of agglomeration, while trace amounts of water (0.01 and 0.05% m/m) showed the opposite effect. The observed phenomena are discussed on basis of the DLVO-theory, supplemented with considerations about forces due to gravity, shear and liquid bridge formation, and the kinetics of agglomeration
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