Formulation Optimization of Selective Laser Sintering 3D-Printed Tablets of Clindamycin Palmitate Hydrochloride by Response Surface Methodology

Abstract

The aims of the current study were to develop and evaluate clindamycin palmitate hydrochloride (CPH) 3D-printed tablets (printlets) manufactured by selective laser sintering (SLS). Optimization of the formulation was performed by studying the effect of formulation and process factors on critical quality attributes of the printlets. The independent factors studied were laser scanning speed, microcrystalline cellulose (MCC), and lactose monohydrate (LMH) concentration. The responses measured were printlets weight, hardness, disintegration time (DT), and dissolution in 30 min. The printlets were characterized for content uniformity, chemical interactions, crystallinity, drug distribution, morphology, and porosity. The laser scanning speed showed statistically significant effects on all the studied dependent responses (p < 0.05). MCC showed statistically significant effects on hardness, DT, and dissolution (p < 0.05), while LMH showed statistically significant effect on hardness and dissolution (p < 0.05). The model was validated by an independent formulation, and empirical values were in close agreement with model-predicted values. X-ray powder diffraction and differential scanning calorimetry data suggested a decrease in crystallinity of the LMH in the printlets. X-ray micro-CT scanning showed porous microstructure of the printlets with a porosity 24.4% and 31.1% for the printlets printed at 200 and 300 mm/s laser speed, respectively. In summary, the SLS method provides an opportunity to fabricate customized dosage forms as per patients' need.

Keywords: 3D printing; Box-Behnken; NIR-chemical imaging; X-ray micro-CT; clindamycin palmitate hydrochloride; dissolution; selective laser sintering.