Improved initial burst of estradiol organogel as long-termin situdrug delivery implant: formulation,in vitroandin vivocharacterization

Three 'D's: Design approach, dimensional printing, and drug delivery systems as promising tools in healthcare applications

The development of pharmaceutical drug products is required for the treatment of disease, which has resulted in an increasing number of approvals by regulatory agencies across the globe. To establish a hassle-free manufacturing process, the systematic use of a quality-by-design (QbD) approach combined with process analytical technology (PAT) and printing techniques can revolutionize healthcare applications. Printing technology has been emerged in various dimensions, such as 3D, 4D, and 5D printing, with respect to their production capabilities, durability, and accuracy of pharmaceutical manufacturing, which can efficiently deliver novel patient-centric healthcare products with holistic characteristics. In this review, we provide current trends in pharmaceutical product development using a design approach and high-quality printing techniques.

Fabrication of PLGA in situ forming implants and study on their correlation of in vitro release profiles with in vivo performances

In this study, a novel PLGA in situ forming implants (ISFIs) were fabricated and methods for testing the in vitro release profiles were also developed. The correlations between in vitro release profiles and in vivo performances (in vitro-in vivo correlation, IVIVC) were also studied. PLGA with different molecular weights were selected as the polymeric matrix. Biocompatible N-methy1-2-pyrrolidone (NMP) or glyceryl triacetate (GTA) were used as the solvents with the ratios of NMP/GTA from 60/40 (vol/vol) to 20/80 (vol/vol). Eprinomectin (EPR) was chosen as the model therapeutic. In vitro release profiles of the EPR-loaded PLGA ISFIs were investigated using various methods (i.e. 'tubule' sample-and-separate and dialysis method). Sprague-Dawley rats were used to study the in vivo pharmacokinetics of EPR-loaded PLGA ISFIs. The release data obtained via 'tubule' sample-separate method had a good IVIVC (Level A, R² > 0.99). These results showed that the 'tubule' sample-separate method was capable of discriminating the EPR-loaded ISFIs which were equivalent in formulation composition with manufacturing differences. Meanwhile, this method could be used to predict the in vivo performances of ISFIs in the investigated animal model.

Organogels based on amino acid derivatives and their optimization for drug release using response surface methodology

Organogels are excellent drug carrier for controlled release. Organogels based on amino acid derivatives has been widely used in the area of drug delivery. In this study, a series of the organogel system based on amino acid derivatives gelators was designed and prepared to investigate the structure-property correlation in organogels. To investigate the factors that influence the property of drug release, we varied the formulation in the organogels: gelator structure, gelator concentration, volume of antigelation solvent, and drug loading. Through the Box-Behnken tests, the optimum organogel formulation in vitro was obtained. The self-healing properties of the organogel have been utilised for injection of a model lipophilic risperidone in situ, and sustained release of the drug has been studied over about one week in vivo. In conclusion, the gelation ability of gelators could be adjusted by the gelator structure. Gel property is related with the whole composition of the formulation. As drug carrier, the drug release property of organogels is affected by multiple factors. Our investigation of the gel release property will play a theoretical guiding role in the application in the in situ drug delivery system.

A novel flunarizine hydrochloride-loaded organogel for intraocular drug delivery in situ: Design, physicochemical characteristics and inspection

We developed a safe and efficacious drug delivery system for treatment of brain diseases. A novel in-situ gel system was prepared using soybean oil, stearic acid and N-methyl-2-pyrrolidinone (NMP) (10:1:3, v/w/v). This system had low viscosity as a sol in vitro and turned into a solid or semi-solid gel in situ after administration. The poorly water-soluble drug flunarizine hydrochloride (FNZ) was incorporated into this "organogel" system. Organogel-FNZ was characterized by light microscopy, differential scanning calorimetry (DSC) and rheology. Drug release in vitro was investigated. The initial "burst" effect did not occur in organogel-FNZ, which is different from other gels formed in situ. Pharmacokinetic studies were undertaken in rats using gel administration (14 mg kg^-1), intravenous administration (5 mg kg^-1) and administration using drops (14 mg kg^-1). Organogel-FNZ could reduce the clearance rate and prolong the duration of action, in the plasma and brain tissues of rats. The peak serum concentration, area under the curve and absolute bioavailability of the organogel-FNZ group were higher than those of the intraocular- drops group. Organogel-FNZ is a promising drug-delivery system for treatment of brain diseases by intraocular administration.

Self-assembled drug delivery system based on low-molecular-weight bis-amide organogelator: synthesis, properties and in vivo evaluation

CONTEXT

Orgnaogels based on amino acid derivatives have been widely used in the area of drug delivery.

OBJECTIVE

An organogel system based on l-lysine derivatives was designed and prepared to induce a thermal sensitive implant with higher transition temperature, better mechanical strength, and shorter gelation time.

MATERIALS AND METHODS

The organogel was prepared by injectable soybean oil and methyl (S)-2,5-ditetradecanamidopentanoate (MDP), which was synthesized for the first time. Candesartan cilexetil (CC) was chosen as model drug. Different formulations were designed and optimized by response surface method. Thermal, rheology properties, and gelation kinetics of the optimized formulation had been characterized. The release behaviors in vitro, as well as in vivo were evaluated in comparison with the oily solution of drugs. Finally, the local inflammation response of in situ organogel was assessed by histological analysis.

RESULTS AND DISCUSSION

Results showed that the synthesized gelator, MDP, had a good gelation ability and the organogels obtained via the self-assembly of gelators in vegetable oils exhibited great thermal and rheology properties, which guaranteed their state in body. In vivo pharmacokinetic demonstrated that the organogel formulation could extend the drug release and maintain a therapeutically effective plasma concentration at least 10 d. In addition, this implant showed acceptable moderate inflammation.

CONCLUSION

The in situ forming l-lysine-derivative-based organogel could be a promising matrix for sustained drug delivery of the drugs with low solubility.

Feasibility of poly (ϵ-caprolactone-co-DL-lactide) as a biodegradable material for in situ forming implants: evaluation of drug release and in vivo degradation

The purpose of this study was to evaluate the technical feasibility of poly (ϵ-caprolactone-co-DL-lactide), P (CL/DL-LA), for injectable in situ forming implants (ISFI). The ISFI was prepared by dissolving P (CL/DL-LA) in N-methyl-2-pyrrolidone (NMP), and Testosterone undecanoate (TU) was used as model drug. The effect of various polymer concentrations, molecular weights (Mws) and drug loads on the drug release from the TU-loaded ISFI systems was investigated in vitro. The release of TU-loaded ISFI was also evaluated in rats. In addition, a subcutaneous rabbit model was used to evaluate the degradation and foreign-body reaction of P (CL/DL-LA) ISFI. The use of higher concentration of P (CL/DL-LA) with higher molecule weight and larger CL:DL-LA monomer ratio for the TU-loaded ISFI gave a slower drug release. The ISFI of 80/20 P (CL/DL-LA) (Mw 61 753):NMP 20:80 with 16% TU formulation increased serum testosterone levels in rats over a period of three months. The in vivo degradation and biocompatibility study of ISFI shows that P (CL/DL-LA) degrades by a process of bulk degradation and that the foreign-body reaction of this biomaterial is relatively mild. In summary, our investigations demonstrate that in situ parenteral drug delivery systems can be obtained from P (CL/DL-LA) solutions.