*8.3. Stability Studies*

### 8.3.1. Thermodynamic Stability Tests

Selected formulations were subjected to different thermodynamic stability tests. Only those formulations that survived dispersion stability tests were selected for further study [21].

### 8.3.2. Heating Cooling Cycle

All samples were placed between refrigerator temperatures of 4 ◦C and 45 ◦C for six cycles with storage at each temperature for not less than 48 h and were then studied. Those formulations that were stable at these temperatures were subjected to centrifugation.

### 8.3.3. Centrifugation

Those formulations that passed were centrifuged at 3500 rpm for 30 min using centrifuge. The formulations that did not show any phase separation were taken for further tests.

### 8.3.4. Freeze-Thaw cycle

Those samples that passed the centrifugation test were placed between –21 ◦C and +25 ◦C for three freeze-thaw cycles with storage at each temperature for not less than 48 h.

### 8.3.5. Statistical Analysis

The statistical analysis was performed using one-way analysis of variance (ANOVA) and was used to compare the results of different formulations. A *p* value of 0.05 was considered to be statistically significant (GraphPad Prism version 6.03, Boston, MA, USA). The characterization data were expressed as the means of three experiments ± SD.

**Author Contributions:** Conceptualization, M.G., R.V. and R.D.; methodology, G.K.; software, N.M.; validation, P.D. and R.C.P.; formal analysis, V.P.V.; investigation, P.P.; resources, K.C.; data curation, K.V. and P.P.; writing—original draft preparation, M.G., R.V. and G.K.; writing—review and editing, R.D., N.M., P.D. and R.C.P.; visualization, M.G.; supervision, R.V.; project administration, G.K.; funding acquisition, G.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through the Large Groups Project under grant number RGP2/150/44.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The authors extend their appreciation to the Deanship of Scientific research at King Khalid University, Saudi Arabia, for funding this work through the Large Groups Project under grant number RGP2/150/44.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **References**


**Disclaimer/Publisher's Note:** The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
