Jun.28,2007  39  US 2007/0148124 Al  diluted  Lactobacillus  spp. is added. Commercially-available  penicillin/streptomycin solution at a high-test concentration  of 1.25 U/ml and 1.25 µg/ml, respectively, is used as the  positive control. The plates are incubated for 24  hr at 37°  C.  in a Gas Pak CO$_{2 }$ bag, and bacterial growth is determined by  measurement of optical density at 490 mn using a 96-well  spectrophotometric plate reader. All determinations are per› formed with six  ‰  Log dilutions from a high test concen› tration in triplicate.  [0335]  The data obtained are depicted in Table 11:  [0338]  The data further show that there was a measurable  differential between activity against HIV-lnrn(CXCR4) and  HIV-lBaL (CCR5) when compounds were tested using a  virus attachment assay (Table 9). In these experiments, DS  was clearly able to inhibit HIV-1 Bau albeit at a reduced level  as was the case for all compounds tested against this strain  of virus (Table 9). Without wishing to be bound, it is  believed that the real differences in activity arose when the  compounds were tested in a cell-associated transmission  assay (Table 10).  It should be noted that the degree of change  in trimellityl-containing polymers roughly correlated with  * All efficacy and toxicity values for TAK 779 are in nM; for AMD 3100 are in µM; and for anionic  polymers are in weight percent polymer. These data represent the averages of three or more independent  experiments. The Standard Deviation was obtained at each polymer concentration tested and ranged  between 0.6 and 8% oftbe data points normalized to percent viral inbibition or percent cell viability.  tThe percentage of benzoic acid substituted per total  dry  weight of polymer.  §The average molecular weight for HPMCT-37 is 30 kD, for all otber polymers it is ~50 kD.  [0336]  The data indicate that all polyanions tested were  relatively ineffective as inhibitors of  lactobacilli  growth.  The selectivity index between the concentration needed to  inhibit 50%  Lactobacilli  growth and that needed to inhibit  HIV-1 becomes larger than that obtained when using cellular  cytotoxicity as the numerator. In addition, the bacterial  inhibition assay is set up to allow for a 24  hr exposure to test  compound, which is not a likely regimen for human use.  [0337]  The data illustrate hereinabove, in a variety of  assay formats, that HPMCT polymer is quite effective at  inhibiting HIV-1 and that the extent of inhibition can be  modulated by the degree of trimellityl substitution on the  cellulose backbone. What separates HPMCT polymer from  the similar cellulose-based polymers (CAP and HPMCP  polymers) is its ability to remain dissociated in solution and  molecularly dispersed even after exposure to a low pH  enviromnent. For example, while all four cellulose-based  polymers tested were effective inhibitors of HIV-lIIB after  a short duration of exposure using assay conditions that were  basically neutral (Table 2), the exposure of CAP to a low pH  enviromnent for even a brief period of time dramatically  lowered its antiviral effectiveness (Tables 6 and 7). The  effect of low pH on phthalate-containing polymers was  further visualized by monitoring the solubility and dissocia› tion of CAP over a wide range of pH conditions (FIG.  10).  Monitoring the combined effect of both solubility and dis› sociation on CAP, we determined that less than 10% of the  original polymer is available when the pH drops to 4.0  before readjusting to neutral. The reason that not more CAP  is available once the pH has been rapidly neutralized under  these assay conditions is simply due to the long dissolution  time of these polymers once they have fallen out of solution.  the degree of carboxylic acid substitution. With the com› parison of the different HPMCT lots that minor variations in  the degree of trimellityl substitution has a dramatic impact  on the antiviral efficacy of the polymer, especially with  respect to its activity against CCR5 virus (Tables 9, 10, and  11).  [0339]  Without wishing to be bound, it is believed that the  overall average molecular weight of the polymer can also  play a role in their antiviral efficacy, as noted for HPMCT-37  (average molecular weight 30 kD).  [0340]  The ability of additional compounds of the present  invention to inhibit additional viral strains were determined.  In the following examples, the antiviral profile of PSMA  (poly styrene alt maleic acid) and hydroxy propyl methy› cellulose trimellitate (HPMCT), both of which are prepared  as described herein were determined on various viral strains.  [0341]  Various assays were utilized, the protocol of which  are described below.  [0342]  The protocol was described in Example 13, the  contents of which are incorporated by reference.  [0343]  When relatively large numbers (10 or more) oftest  compounds are submitted at the same time from a single  sponsor, the compounds are evaluated in a 2-concentration  test. In this procedure, 2 concentrations (200, 20 µg/ml  unless otherwise directed) are tested. These are diluted 1 :2  when virus is added, making final concentrations 100 and 10  µg/ml. The standard CPE test uses an 18 h monolayer  (80-100% confluent) of the appropriate cells, medium is  1. VBI (Virus Attachment Inhibitor Assay)  2. Rapid Screening Assay  Examples 17-18  TABLE 11  Effect of Trimellityl content on cell-associated HIV-1 infectivity.  CXCR4 Virus HIV-1  Assay Virus HN-1  IR csF§  Compound*  ICso  IC90  CCso  Tiso  ICso  IC90  CCso  Tiso  TAK 779  >10  >10  >10  NA  0.002  0.55  >10  >10,000  AMD 3100  0.005  0.06  >10  >2,000  >10  >10  >10  NA  CAP-35t  0.06  7.45  >25  >415  2.93  >25  >25  >8.50  HPMCT-29  >25  >25  >25  NA  12.7  >25  >25  >1.97  HPMCT-35  0.18  13.7  9.7  53.89  7.82  19.8  9.07  1.16  HPMCT-36  0.18  >25  >25  >138  8.22  >25  >25  >3  HPMCT-37  0.76  23.2  15.5  20.39  5.5  18.5  19.6  3.56  HPMCT-49  0.00025  2.61  9.32  37,200  0.006  0.12  9.91  1,651 