Preparation and Characterization of Benzathine Penicillin G Solid Dispersions Using Different Hydrophilic Carriers

Several technical factors related to penicillin G intramuscular injection can affect its bioavailability and hence reduce the efficacy of rheumatic fever prevention program. When small amount of diluent is used, the powder is not completely dissolved and the thick suspension frequently causes obstruction of injection needle. The study aimed to characterize the solid-state properties of solid dispersion systems of benzathine penicillin G (BPG) prepared with hydrophilic carriers by applying solvent evaporation method. The results of spectroscopic studies; Fourier transform-infra red (FTIR), Nuclear Magnetic Spectroscopy (1HNMR) and Differential Scanning Calorimetry (DSC) revealed no chemical interaction between the drug and carriers. No significant changes in drug crystalline state were observed by X-ray diffraction and Scanning Electron Microscope (SEM) studies, even with using amorphous carriers; polyvinyl pyrrolidone (PVP-K30) and hydroxypropyl methylcellulose (HPMC). All the prepared solid dispersions demonstrated 76-93% yield and % drug content dependent on the polymer type and concentration. The hydrophilic polymers demonstrated potential effect on improving the flowability, wettability and dissolution characters of the drug. The results revealed that it is possible to enhance the dissolution rate of BPG (hydrophobic drug) by increasing the surface area of the drug adsorbed on the surface of hydrophilic polymer by solid dispersion method. Finally, solid dispersion BPG: PEG 4000 at ratio 50:50 gave uniform flowability of the powder (around 30), wettability (12 min) and faster dissolution rates among all the formulations. Thus, it was selected as the best formulation in this study

Preparation and Characterization of Benzathine Penicillin G Solid Dispersions Using Different Hydrophilic Carriers

Several technical factors related to penicillin G intramuscular injection can affect its bioavailability and hence reduce the efficacy of rheumatic fever prevention program. When small amount of diluent is used, the powder is not completely dissolved and the thick suspension frequently causes obstruction of injection needle. The study aimed to characterize the solid-state properties of solid dispersion systems of benzathine penicillin G (BPG) prepared with hydrophilic carriers by applying solvent evaporation method. The results of spectroscopic studies; Fourier transform-infra red (FTIR), Nuclear Magnetic Spectroscopy (1HNMR) and Differential Scanning Calorimetry (DSC) revealed no chemical interaction between the drug and carriers. No significant changes in drug crystalline state were observed by X-ray diffraction and Scanning Electron Microscope (SEM) studies, even with using amorphous carriers; polyvinyl pyrrolidone (PVP-K30) and hydroxypropyl methylcellulose (HPMC). All the prepared solid dispersions demonstrated 76-93% yield and % drug content dependent on the polymer type and concentration. The hydrophilic polymers demonstrated potential effect on improving the flowability, wettability and dissolution characters of the drug. The results revealed that it is possible to enhance the dissolution rate of BPG (hydrophobic drug) by increasing the surface area of the drug adsorbed on the surface of hydrophilic polymer by solid dispersion method. Finally, solid dispersion BPG: PEG 4000 at ratio 50:50 gave uniform flowability of the powder (around 30), wettability (12 min) and faster dissolution rates among all the formulations. Thus, it was selected as the best formulation in this study

An Approach to Enhance Dissolution Rate of Tamoxifen Citrate

We tested the solubility and dissolution of tamoxifen citrate to ascertain the optimal conditions for faster dissolution. Using the solvent evaporation method and hydrophilic carriers, we formulated tamoxifen citrate (TC) that contained solid dispersions (SDs). We increased the solubility and dissolution rate of TC with a solid dispersion system that consisted of polyethylene glycol (PEG-6000), beta-cyclodextrin (β-CD), and a combination of carriers. Physicochemical characteristics of solubility (mg/ml) were found to be 0.987±0.04 (water), 1.324±0.05 (6.8pH PBS), and 1.156±0.03 (7.4 pH PBS) for F5 formulation, percentage yield was between 98.74 ± 1.11% and 99.06 ± 0.58%, drug content was between 98.06±0.58 and 99.06±1.10, and dissolution studies binary complex showed a faster release of TC as compared to a single polymer and pure drug. Furthermore, thermal properties, physicochemical drug and polymer interaction, crystal properties, and morphology were determined using differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), X-ray differential studies, and scanning electron microscopy. We used the same proportion of carrier concentrations of the formulations to calculate the solubility of TC. Our results demonstrated that increased concentrations of β-C yielded an improved solubility of TC, which was two times higher than pure TC. The uniformity in drug content was 97.99 %. A quicker drug release occurred from the binary complex formulation as seen in the dissolution profile. FTIR demonstrated an absence in the physicochemical interaction between the drug and carriers. The drug was also found to be dispersed in the amorphous state as revealed by DSC and XRD. The drug concentration did not vary during various storage conditions. Our in vivo studies demonstrated that SD displayed significantly higher values of Cmax (p < 0.05) and AUC0-24 (p < 0.05) as compared to free TC. Furthermore, Tmax in SD was significantly lower (p < 0.05), as compared to free TC