Formulation and evaluation of microspheres of diltiazem hydrochloride

DoE approach for development of localized controlled release microspheres of Vancomycin for treatment of septic arthritis

Background

Septic arthritis is a worse condition of RA that is associated with significant morbidity and mortality. Septic arthritis develops due to direct introduction or invasion of pathogens. The objective of the present study was to formulate Vancomycin hydrochloride-loaded microspheres (VMS) based on Box–Behnken design (BBD) and evaluate its efficacy against septic arthritis. The intraarticular administration of optimized Vancomycin hydrochloride-loaded microspheres (OVMS) can reduce dose size, dosing frequency and systemic exposure with local targeted delivery.

Results

OVMS was further characterized for its drug–polymer compatibility using differential scanning calorimetry and Fourier transmission infrared spectroscopy. In vitro antibacterial activity was determined using the cup–plate method and in vivo anti-arthritic efficacy was evaluated by gross examination of septic arthritis. DSC and FTIR studies exhibited no interaction or incompatibilities between the drug and polymer. SEM images revealed that OVMS were spherical. It followed the first-order release rate according to Fick's law. The micromeritic properties indicated good flow property of OVMS. The zone of inhibition by OVMS was 1.5 cm against S. aureus. In vivo antibacterial study revealed that OVMS was significant in reducing septic arthritis and bacterial load, i.e., 110.1 CFU/ml in comparison with the control group (850 CFU/ml).

Conclusions

Thus, OVMS may be used as an effective formulation for the treatment of septic arthritis as compared to marketed IV vancomycin injection after clinical studies.

Formulation and in vitro evaluation of taste-masked oro-dispersible dosage form of diltiazem hydrochloride

Diltiazem hydrochloride is a calcium channel blocker generally indicated for the treatment of angina and hypertension, and it is extensively metabolized due to the hepatic metabolism. Formulation of diltiazem hydrochloride into an oro-dispersible dosage form can provide fast relief with higher bioavailability. The bitter taste of the drug should be masked to formulate it in a palatable form. In the present work, an attempt was made to mask the taste by complexation technique, with a formulation into an oro-dispersible dosage form, using superdisintegrants Doshion P544, crospovidone (CP) and sodium starch glycolate (SSG). The complexes of diltiazem hydrochloride with β-CD (1:1 molar ratio) were prepared by kneading, co-evaporation, co-grounding, freeze-drying and melting methods. Phase solubility showed stability constant 819.13M-1. Prepared inclusion complexes were evaluated for taste masking and characterized by I.R, XRD, DSC. Using the drug β-CD complex, oro-dispersible tablets were prepared and evaluated for hardness, friability, weight variation, thickness, disintegrating time (DT), dissolution rate and taste. Formulations with 4 % Doshion, 8 % CP and 4 % SSG showed DT of 0.54, 0.35 and 1.23 minutes, respectively.