Amorphous solid dispersions (ASDs) are among the most popular and widely studied solubility enhancement techniques. Since their inception in the early 1960s, the formulation development of ASDs has undergone tremendous progress. For instance, the method of preparing ASDs evolved from solvent-based approaches to solvent-free methods such as hot melt extrusion and Kinetisol^®. The formulation approaches have advanced from employing a single polymeric carrier to multiple carriers with plasticizers to improve the stability and performance of ASDs. Major excipient manufacturers recognized the potential of ASDs and began introducing specialty excipients ideal for formulating ASDs. In addition to traditional techniques such as differential scanning calorimeter (DSC) and X-ray crystallography, recent innovations such as nano-tomography, transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray microscopy support a better understanding of the microstructure of ASDs. The purpose of this review is to highlight the recent advancements in the field of ASDs with respect to formulation approaches, methods of preparation, and advanced characterization techniques

In recent years, with the increasing patient population, the need for complex and patient-centric medications has increased enormously. Traditional manufacturing techniques such as direct blending, high shear granulation, and dry granulation can be used to develop simple solid oral medications. However, it is well known that “one size fits all” is not true for pharmaceutical medicines. Depending on the age, sex, and disease state, each patient might need a different dose, combination of medicines, and drug release pattern from the medications. By employing traditional practices, developing patient-centric medications remains challenging and unaddressed. Over the last few years, much research has been conducted exploring various additive manufacturing techniques for developing on-demand, complex, and patient-centric medications. Among all the techniques, nozzle-based additive manufacturing platforms such as pressure-assisted microsyringe (PAM) and fused deposition modeling (FDM) have been investigated thoroughly to develop various medications. Both nozzle-based techniques involve the application of thermal energy. However, PAM can also be operated under ambient conditions to process semi-solid materials. Nozzle-based techniques can also be paired with the hot melt extrusion (HME) process for establishing a continuous manufacturing platform by employing various in-line process analytical technology (PAT) tools for monitoring critical process parameters (CPPs) and critical material attributes (CMAs) for delivering safe, efficacious, and quality medications to the patient population without compromising critical quality attributes (CQAs). This review covers an in-depth discussion of various critical parameters and their influence on product quality, along with a note on the continuous manufacturing process, quality by design, and future perspectives.

Objective: The current work involves formulation development of nanostructured lipid carrier (NLC) of eperisone hydrochloride (EPE) using quality by design (QbD) approach. Materials and Methods: Initial screening of solid and liquid lipids was performed based on the Hansen solubility parameters of EPE and the lipids and later confirmed using saturation solubility studies. The optimum formulation was identified using three-squared randomized full factorial design. High shear homogenization coupled with ultrasonication was used to prepare the NLCs. The effect of the independent variables on the dependent variables was analyzed using response surface graphs and ANOVA. The optimized formulation is characterized for mean particle size, zeta potential, entrapment efficiency, in vitro drug release and subjected to stability testing. Results and Discussion: Precirol^® ATO 5, Capryol^TM 90, and Pluronic^® F127 are found to be ideal solid lipid, liquid lipid and surfactant respectively based on the initial screening. Amount of lipid mixture (X1) and the amount of surfactant (X2) were selected as independent variables and the entrapment efficiency (Y1), mean particle size (Y2) and zeta potential (Y3) were selected as dependent variables. The optimized NLC formulation has mean particle size of 175 nm, zeta potential -24.4 mV and entrapment efficiency of 78.64%. The in vitro drug release data suggested that the drug release follows Quasi-Fickian diffusion. The stability data showed that the NLCs are stable up to 3 months at refrigerated conditions. Conclusions: The Hansen solubility parameter approach coupled with QbD is a powerful tool for formulation of sustained release NLCs of highly soluble poorly soluble drugs. Keywords: Nanostructured lipid carrier, Solubility Parameters, Nanoparticles, Lipid based drug delivery, Quality by Design

In recent years, with the increasing patient population, the need for complex and patient-centric medications has increased enormously. Traditional manufacturing techniques such as direct blending, high shear granulation, and dry granulation can develop simple solid oral medications. However, it is well known that “one size fits all” is not true for pharmaceutical medicines. Depending on the age, sex, and disease state, each patient might need a different dose, combination of medicines, and drug release pattern from the medications. By employing traditional practices, developing patient-centric medications remains challenging and unaddressed. Over the last few years, much research has been conducted exploring various additive manufacturing techniques for developing on-demand, complex, and patient-centric medications. Among all the techniques, nozzle-based additive manufacturing platforms such as pressure-assisted microsyringe (PAM) and fused deposition modeling (FDM) have been investigated thoroughly to develop various medications. Both nozzle-based techniques involve the application of thermal energy. However, PAM can also be operated under ambient conditions to process semi-solid materials. The nozzle-based techniques can also be paired with the hot melt extrusion (HME) process for establishing a continuous manufacturing platform by employing various in-line process analytical technology tools (PAT) for monitoring the critical process parameters (CPPs) and critical material attributes (CMAs) for delivering safe, efficacious and quality medications to the patient population without compromising the critical quality attributes (CQAs). The review covers an in-depth discussion of various critical parameters and their influence on product quality, along with a note on the continuous manufacturing process, quality by design, and future perspectives.