Injectable controlled-release formulations of progestogen drugs
Inventors
Fu, Zengli • Ugwu, Sydney • He, James
Assignees
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Publication Number
US-12433841-B2
Publication Date
2025-10-07
Expiration Date
Abstract
The present invention relates to injectable microspheres and formulations comprising the microspheres for controlled release of progestogen hormones.
Core Innovation
The invention relates to an injectable sustained-release formulation comprising microspheres comprising progesterone and a biodegradable composition comprising one or more poly(lactic-co-glycolic acid) copolymers (PLGA), together with a diluent solution in which the microspheres are suspended. The PLGA copolymer is defined by a molar ratio of lactide to glycolide of about 50:50, about 75:25, or a combination of PLGA copolymers with those molar ratios, and a molecular weight range of between about 4 kD and 75 kD. The progesterone is present in an amount between about 35% and about 50% by weight of the microspheres.
The microspheres encapsulating the progesterone have a mean diameter between about 50 μm and about 100 μm. The formulation is characterized by an in vitro release profile graph that exhibits a linear correlation coefficient equal to or greater than 0.75 from a 0,0 time point to a 70% progesterone release point on the graph. This in vitro release profile is determined under defined release medium and shaking conditions.
The invention also provides a diluent solution associated with the microspheres, and dependent claims specify diluent excipient components. In addition, the invention includes methods of making the injectable sustained-release formulation using an oil-in-water emulsion processing sequence to form solid drug-loaded microspheres, drying the microspheres, and suspending them in the diluent solution. Further dependent claims narrow therapeutic use for preventing pregnancy or supporting fertility and for treating gynecological disorders.
Claims Coverage
The independent claim set includes one independent claim defining an injectable sustained-release formulation, with five inventive features centered on progesterone-loaded PLGA microspheres, defined PLGA composition, loading, size, and a linear in vitro release criterion. The remaining claim set refines the release profile, diluent excipients, PLGA details, manufacturing, and therapeutic use.
Injectable sustained-release progesterone/PLGA microspheres in defined diluent
An injectable sustained-release formulation comprising microspheres comprising progesterone and a biodegradable composition comprising one or more PLGA copolymers, and a diluent solution in which the microspheres are suspended.
Defined PLGA lactide:glycolide ratio and molecular weight
The one or more PLGA copolymers is a PLGA copolymer with a molar ratio of lactide to glycolide of about 50:50 or about 75:25, or a combination of PLGA copolymers with a molar ratio of lactide to glycolide of about 50:50 and 75:25 and a molecular weight in the range between 4 kD and 75 kD.
Progesterone loading in microspheres
Progesterone is present in an amount of between about 35% and about 50% by weight of the microspheres.
Microsphere size range
The microspheres encapsulating the progesterone have a mean diameter of between about 50 μm and about 100 μm.
Linear in vitro release profile criterion
An in vitro release profile graph exhibits a linear correlation coefficient equal to or greater than 0.75 from a 0,0 time point to a 70% progesterone release point on the graph under defined release medium and shaking conditions.
Overall, the claim coverage centers on microspheres encapsulating progesterone in biodegradable PLGA with specified lactide:glycolide molar ratios and molecular weight range, defined progesterone loading and microsphere mean diameter, and an in vitro release profile with a specified linear correlation criterion. Dependent claims further refine the release model, specify particular diluent components, narrow PLGA end-group and molecular-weight subranges, add manufacturing sequence limitations, and narrow gynecological disorder treatment to named disorders.
Stated Advantages
Provides an in vitro release profile graph exhibiting linear correlation coefficient equal to or greater than 0.75 from a 0,0 time point to a 70% progesterone release point.
Provides an in vitro release profile graph with linear correlation coefficient equal to or greater than 0.80 up to an 80% progesterone release point.
Provides a specified time to 80% progesterone release (about 6 to 8 days) under in vitro testing.
Documented Applications
Preventing pregnancy or supporting fertility via a local injection of the disclosed injectable sustained-release formulation.
Treating gynecological disorders selected from secondary amenorrhea, endometriosis, abnormal uterine bleeding due to hormonal imbalance, and acne.
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