Triethanolamine

SSD was kindly supplied as a gratis sample by Bharat Parenteral, Baroda, Gujarat, India and GMO by Chemdyes Corporation, Rajkot. Polyvinyl alcohol, carbopol 934, carbopol 940, and propyl paraben sodium salt and triethanolamine were obtained from Loba chemie Pvt Ltd., (Mumbai, India). Poloxamer 407 was purchased from BASF chemical company (Mumbai). Di-sodium ethylenediaminetetraacetic acid (EDTA), sodium benzoate, Methylparaben, dist. Water, triethanolamine, ammonia, ammonium phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, sodium sulfate, sodium chloride, and methanol were purchased from SD Fine Chemicals, Mumbai. A. vera gel was supplied by Vasu pharmaceutical, Baroda.

Polyvinylpyrrolidone (PVP) that has a molecular weight of 1,300 kDa, CD with a molecular weight of 1.303 kDa, ethyl alcohol (≥99.5 %) and all buffer salts used, i.e., potassium phosphate monobasic, sodium phosphate dibasic, sodium chloride and potassium chloride, were bought from Sigma-Aldrich (St. Louis, MO, USA). Triethanolamine was obtained from Loba Chemie (Mumbai, India) and the ribavirin (Mw = 244.20) was purchased from Biosynthesis Carbosynth (Compton, UK). P. aeruginosa – ATCC 27853, ATCC 1744, and PAO1, C. albicans – ATCC 66027, Staphylococcus aureus (S. aureus)ATCC 29,213 and MRSA—ATCC 43300, Escherichia coli (E. coli) ATCC 25922, and Acinetobacter baumannii (A. baumannii) ATCC 747 reference microbes were obtained from the American Type Culture Collection (ATCC) (Manassas, VA, USA). Clinical isolates of P. aeruginosa (7067), E. coli (1060) and A. baumannii (3034) were also used in this study. Mueller–Hinton agar (MHA) and Mueller-Hinton broth (MHB) were purchased from Scharlau (Barcelona, Spain) and afterwards prepared according to the manufacturer's instructions. Water used in experimental preparations was distilled via the Milli-Q® IQ 7005 Purification System (Millipore SAS Molsheim, France).

PVP polymer with a molecular weight of (∼1,300,000), HPLC grade dimethylformamide (DMF), ethanol (≥99.5 %), acetonitrile, phosphate buffer saline (PBS) tablets, and chloroform were purchased from Sigma-Aldrich (St. Louis, MO, USA).). The preparation of the PBS solution was performed by dissolving 5 tablets of PBS in 1L of distilled water and then adjusting the pH to 6.8 using 5 M HCl. Sildenafil citrate (CAS No. 139755–83-2), which will be referred to as sildenafil throughout the manuscript, was gifted from Jazeera Pharmaceutical Industry (JPI; Riyadh, Saudi Arabia),. Glycyrrhizin was bought from Azur Chemical and Pharmaceutical, (Hyderabad, India), while triethanolamine was obtained from Loba Chemie (Mumbai, India). Milli Q Millipore (Billerica, MA, USA) was used to generate distilled water.