Preformulation Characterization of Griffithsin, a Biopharmaceutical Candidate for HIV Prevention.

Griffithsin (GRFT) has shown potent anti-HIV activity, and it is being developed as a drug candidate for HIV prevention. Successful implementation requires thorough understanding of its preformulation characterization. In this work, preformulation assessments were conducted to characterize GRFT and identify its degradation pathways under selected conditions of temperature, light, pH, shear, ionic strength, and oxidation. Compatibility with vaginal fluid simulant, vaginal enzymes, Lactobacillus spp., and human cervicovaginal secretions was assessed. The purity, melting temperature, and HIV gp120-binding affinity of GRFT stored at 4°C and 25°C in phosphate-buffered saline (PBS) were assessed for 2 years. Chemical modifications were evaluated by intact mass analysis and peptide sequencing. Excised human ectocervical tissue permeability and localization of GRFT were evaluated. Our results demonstrated GRFT to be safe and stable under all the preformulation assessment conditions studied except oxidative stress. When GRFT was exposed to hydrogen peroxide or human cervicovaginal secretion, methionine 78 in the protein sequence underwent oxidation. GRFT did not permeate through human cervical tissue but adhered to the superficial epithelial tissue. The 2-year stability study revealed no significant change in GRFT's aggregation, degradation, melting temperature, or gp120-binding affinity despite a slow increase in oxidation over time. These studies elucidated desirable safety and bioactivity profile for GRFT, showing promise as a potential drug candidate for HIV prevention. However, susceptibility to oxidative degradation was identified. Effective protection of GRFT from oxidation is required for further development.

Preferred Physical Characteristics of Vaginal Film Microbicides for HIV Prevention in Pittsburgh Women.

Unprotected heterosexual intercourse is the leading cause of HIV acquisition in women. Due to the complex nature of correct and consistent condom use by both men and women, developing alternative female-controlled HIV prevention options is a global health priority. Vaginal films containing antiretroviral drugs are a potential delivery system for the prevention of HIV acquisition through sexual contact. In this study, we explored women's preferences regarding physical characteristics of microbicide vaginal films through questionnaires and focus groups. Eighty-four sexually active, ethnically diverse women 18-30 years of age from Pittsburgh, Pennsylvania, participated in the study. Women visually and manually examined a variety of vaginal films, as well as three other vaginal products undergoing evaluation for HIV prevention: tablet, ring, and gel. Means and standard deviations or frequencies and 95 % confidence intervals were calculated for questionnaire data. Focus groups were audio-recorded, transcribed verbatim, and coded for content analysis. Women most frequently preferred vaginal films to be smooth and thin (63 %), translucent (48 %), and 2″ × 2″ square size (36 %). Driving these preferences were five major themes: ease and accuracy of use, desire for efficacy, discretion, intravaginal comfort and minimal impact, and minimizing disruption of sexual mood/activities. Women's preferences for various microbicide vaginal film physical attributes represented a balance of multiple values. In general, women desired a comfortable, efficacious, easy to use, and minimally intrusive product.

Assessing the potential of the Woman's Condom for vaginal drug delivery.

BACKGROUND: The Woman's Condom is a new female condom that uses a dissolvable polyvinyl alcohol capsule to simplify vaginal insertion. This preclinical study assessed the feasibility to incorporate an antiviral drug, UC781, into the Woman's Condom capsule, offering a unique drug delivery platform. STUDY DESIGN: UC781 capsules were fabricated using methods from the development of the Woman's Condom capsules as well as those used in vaginal film development. Capsules were characterized to evaluate physical/chemical attributes, Lactobacillus compatibility, in vitro safety and bioactivity, and condom compatibility. RESULTS: Two UC781 capsule platforms were assessed. Capsule masses (mg; mean±SD) for platforms 1 and 2 were 116.50±18.22 and 93.80±8.49, respectively. Thicknesses were 0.0034±0.0004 in and 0.0033±0.0004 in. Disintegration times were 11±3 s and 5±1 s. Puncture strengths were 21.72±3.30 N and 4.02±0.83 N. Water content measured 6.98±1.17% and 7.04±1.92%. UC781 content was 0.59±0.05 mg and 0.77±0.11 mg. Both platforms retained in vitro bioactivity and were nontoxic to TZM-bl cells and Lactobacillus. Short-term storage of UC781 capsules with the Woman's Condom pouch did not decrease condom mechanical integrity. CONCLUSIONS: UC781 was loaded into a polymeric capsule similar to that of the Woman's Condom product. This study highlights the potential use of the Woman's Condom as a platform for vaginal delivery of drugs relevant to sexual/reproductive health, including those for short- or long-acting HIV prevention. IMPLICATIONS: We determined the proof-of-concept feasibility of incorporation of an HIV-preventative microbicide into the Woman's Condom capsule. This study highlights various in vitro physical and chemical evaluations as well as bioactivity and safety assessments necessary for vaginal product development related to female sexual and reproductive health.